feat(resource): refactor heap management & suballocation

Major overhaul of GPU resource/heap management:
- Replace resource pooling and upload buffer logic with transient heap/page-based suballocation in ResourceManager.
- Add support for suballocation and heap flags/types, with D3D12 helpers.
- Remove ICommandBuffer.UploadBuffer/UploadTexture; add UpdateSubResources and CopyBuffer, move upload logic to RenderingContext.
- Refactor D3D12ResourceAllocator/Database for suballocation, heap flags, and mapping.
- Standardize on Handle<GPUBuffer> usage.
- Update meshlet/mesh utilities for new allocation handles and memory pools.
- Refactor RenderGraph and docs to use "heap" terminology.
- Use cpuFrame/gpuFrame consistently for frame sync.
- Add s2h.hlsl, s2h_3d.hlsl, s2h_scatter.hlsl shader debug libs.
- Miscellaneous fixes, cleanup, and dependency updates.

BREAKING CHANGE: Resource pooling and upload APIs replaced with new heap/page-based suballocation system. Update all buffer/texture creation and upload code to use new ResourceManager and ICommandBuffer methods.

src/Editor/Ghost.DSL/ShaderParser/ShaderVisitor.cs

@@ -209,7 +209,7 @@ public class ShaderVisitor : GhostShaderParserBaseVisitor<object>
         if (stop >= start)
         {
             var input = context.Start.InputStream;
-            hlsl.Code = input.GetText(new Antlr4.Runtime.Misc.Interval(start, stop));
+            hlsl.Code = input.GetText(new Interval(start, stop));
         }
 
         return hlsl;

src/Editor/Ghost.Editor/Properties/Resources.Designer.cs

@@ -13,7 +13,7 @@ namespace Ghost.Editor.Properties {
     
     
     /// <summary>
-    ///   A strongly-typed resource class, for looking up localized strings, etc.
+    ///   A strongly-typed heap class, for looking up localized strings, etc.
     /// </summary>
     // This class was auto-generated by the StronglyTypedResourceBuilder
     // class via a tool like ResGen or Visual Studio.
@@ -48,7 +48,7 @@ namespace Ghost.Editor.Properties {
         
         /// <summary>
         ///   Overrides the current thread's CurrentUICulture property for all
-        ///   resource lookups using this strongly typed resource class.
+        ///   heap lookups using this strongly typed heap class.
         /// </summary>
         [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
         internal static global::System.Globalization.CultureInfo Culture {

src/Editor/Ghost.Editor/Themes/DockingDictionary.xaml

@@ -1,6 +1,4 @@
-<ResourceDictionary
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
 
     <ResourceDictionary.MergedDictionaries>
         <ResourceDictionary Source="/View/Controls/Docking/DockingLayout.xaml" />

src/Editor/Ghost.Editor/Utilities/Converters/AssetPathToGlyphConverter.cs

@@ -18,7 +18,7 @@ public partial class AssetPathToGlyphConverter : IValueConverter
 
         var extension = Path.GetExtension(path).ToLowerInvariant();
 
-        // TODO: Use resource dictionary for icons.
+        // TODO: Use heap dictionary for icons.
         return extension switch
         {
             ".ghostscene" => "\uF159",

src/Editor/Ghost.Editor/View/Controls/Docking/DockDocument.xaml

@@ -10,9 +10,10 @@
             <Setter.Value>
                 <ControlTemplate TargetType="local:DockDocument">
                     <Border Background="Transparent">
-                        <ContentPresenter Content="{TemplateBinding Content}"
+                        <ContentPresenter
                             HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
-                                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
+                            VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+                            Content="{TemplateBinding Content}" />
                     </Border>
                 </ControlTemplate>
             </Setter.Value>

src/Editor/Ghost.Editor/View/Controls/Docking/DockGroup.cs

@@ -157,7 +157,7 @@ public partial class DockGroup : DockContainer
                         Content = doc
                     };
 
-                    existingTab.SetBinding(TabViewItem.HeaderProperty, new Microsoft.UI.Xaml.Data.Binding
+                    existingTab.SetBinding(TabViewItem.HeaderProperty, new Binding
                     {
                         Source = doc,
                         Path = new PropertyPath(nameof(DockDocument.Title)),

src/Editor/Ghost.Editor/View/Controls/Docking/DockRegionHighlight.xaml

@@ -7,7 +7,12 @@
         <Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="local:DockRegionHighlight">
-                    <Border Background="{ThemeResource SystemControlHighlightAccentBrush}" Opacity="0.25" BorderBrush="{ThemeResource SystemControlHighlightAccentBrush}" BorderThickness="2" CornerRadius="4" />
+                    <Border
+                        Background="{ThemeResource SystemControlHighlightAccentBrush}"
+                        BorderBrush="{ThemeResource SystemControlHighlightAccentBrush}"
+                        BorderThickness="2"
+                        CornerRadius="4"
+                        Opacity="0.25" />
                 </ControlTemplate>
             </Setter.Value>
         </Setter>

src/Editor/Ghost.Editor/View/Controls/ProjectBrowser.xaml.cs

@@ -108,7 +108,7 @@ internal sealed partial class ProjectBrowser : UserControl
         _isUpdatingSelection = false;
     }
 
-    private async void PART_FilesView_DoubleTapped(object sender, Microsoft.UI.Xaml.Input.DoubleTappedRoutedEventArgs e)
+    private async void PART_FilesView_DoubleTapped(object sender, DoubleTappedRoutedEventArgs e)
     {
         if (PART_FilesView.SelectedItem is ExplorerItem selectedItem)
         {

src/Runtime/Ghost.Core/Ghost.Core.csproj

@@ -22,7 +22,7 @@
   <ItemGroup>
     <PackageReference Include="Misaki.HighPerformance" Version="1.0.6" />
     <PackageReference Include="Misaki.HighPerformance.Jobs" Version="1.5.8" />
-    <PackageReference Include="Misaki.HighPerformance.LowLevel" Version="1.6.3">
+    <PackageReference Include="Misaki.HighPerformance.LowLevel" Version="1.6.9">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>

src/Runtime/Ghost.Graphics.D3D12/D3D12CommandBuffer.cs

@@ -6,6 +6,7 @@ using Misaki.HighPerformance.LowLevel.Utilities;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using TerraFX.Interop.DirectX;
+using TerraFX.Interop.Gdiplus;
 using TerraFX.Interop.Windows;
 
 using static TerraFX.Aliases.D3D_Alias;
@@ -635,7 +636,7 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
         pNativeObject->SetPipelineState(psor.Value);
     }
 
-    public void SetConstantBufferView(uint slot, Handle<RHI.GPUBuffer> buffer)
+    public void SetConstantBufferView(uint slot, Handle<GPUBuffer> buffer)
     {
         AssertNotDisposed();
         ThrowIfNotRecording();
@@ -651,7 +652,7 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
         pNativeObject->SetGraphicsRootConstantBufferView(slot, resource.Get()->GetGPUVirtualAddress());
     }
 
-    public void SetVertexBuffer(uint slot, Handle<RHI.GPUBuffer> buffer, ulong offset = 0)
+    public void SetVertexBuffer(uint slot, Handle<GPUBuffer> buffer, ulong offset = 0)
     {
         AssertNotDisposed();
         ThrowIfNotRecording();
@@ -681,7 +682,7 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
         pNativeObject->IASetVertexBuffers(slot, 1, &vbView);
     }
 
-    public void SetIndexBuffer(Handle<RHI.GPUBuffer> buffer, IndexType type, ulong offset = 0)
+    public void SetIndexBuffer(Handle<GPUBuffer> buffer, IndexType type, ulong offset = 0)
     {
         AssertNotDisposed();
         ThrowIfNotRecording();
@@ -821,7 +822,7 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
         throw new NotImplementedException();
     }
 
-    public void ExecuteIndirect(Handle<RHI.GPUBuffer> argumentBuffer, ulong argumentOffset, Handle<RHI.GPUBuffer> countBuffer, ulong countBufferOffset)
+    public void ExecuteIndirect(Handle<GPUBuffer> argumentBuffer, ulong argumentOffset, Handle<GPUBuffer> countBuffer, ulong countBufferOffset)
     {
         throw new NotImplementedException();
 
@@ -845,57 +846,7 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
 
     }
 
-    public void UploadBuffer<T>(Handle<RHI.GPUBuffer> buffer, params ReadOnlySpan<T> data)
+    public void CopyBuffer(Handle<GPUBuffer> dst, Handle<GPUBuffer> src, ulong dstOffset = 0, ulong srcOffset = 0, ulong numBytes = 0)
-        where T : unmanaged
-    {
-        static void Map(T* pData, nuint size, ulong offset, SharedPtr<ID3D12Resource> resource)
-        {
-            void* pMappedData;
-            resource.Get()->Map(0, null, &pMappedData);
-            MemoryUtility.MemCpy((byte*)pMappedData + offset, pData, size);
-            resource.Get()->Unmap(0, null);
-        }
-
-        AssertNotDisposed();
-        ThrowIfNotRecording();
-#if !DEBUG
-        if (_lastError.Status != Error.None)
-        {
-            return;
-        }
-#endif
-        IncrementCommandCount();
-
-        var pResource = _resourceDatabase.GetResource(buffer.AsResource());
-
-        D3D12_HEAP_PROPERTIES properties;
-        D3D12_HEAP_FLAGS flags;
-        ThrowIfFailed(pResource.Get()->GetHeapProperties(&properties, &flags));
-
-        if (properties.Type == D3D12_HEAP_TYPE_UPLOAD)
-        {
-            fixed (T* pData = data)
-            {
-                Map(pData, (nuint)(data.Length * sizeof(T)), 0, pResource);
-            }
-        }
-        else
-        {
-            var sizeInBytes = (uint)(data.Length * sizeof(T));
-
-            var uploadHandle = _resourceAllocator.CreateTempUploadBuffer(sizeInBytes, out var offset);
-            var uploadResource = _resourceDatabase.GetResource(uploadHandle.AsResource());
-
-            fixed (T* pData = data)
-            {
-                Map(pData, sizeInBytes, offset, uploadResource);
-            }
-
-            pNativeObject->CopyBufferRegion(pResource, 0, uploadResource, offset, sizeInBytes);
-        }
-    }
-
-    public void UploadTexture(Handle<GPUTexture> texture, params ReadOnlySpan<SubResourceData> subresources)
     {
         AssertNotDisposed();
         ThrowIfNotRecording();
@@ -905,47 +856,7 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
             return;
         }
 #endif
-        IncrementCommandCount();
 
-        var resource = _resourceDatabase.GetResource(texture.AsResource());
-
-        var resourceDesc = resource.Get()->GetDesc();
-        var requiredSize = GetRequiredIntermediateSize(resource, 0, (uint)subresources.Length);
-
-        var uploadHandle = _resourceAllocator.CreateTempUploadBuffer(requiredSize, out var offset);
-        var pUploadResource = _resourceDatabase.GetResource(uploadHandle.AsResource());
-
-        var d3d12Subresources = stackalloc D3D12_SUBRESOURCE_DATA[subresources.Length];
-        for (var i = 0; i < subresources.Length; i++)
-        {
-            d3d12Subresources[i] = new D3D12_SUBRESOURCE_DATA
-            {
-                pData = subresources[i].pData,
-                RowPitch = (nint)subresources[i].rowPitch,
-                SlicePitch = (nint)subresources[i].slicePitch
-            };
-        }
-
-        UpdateSubresources(
-            (ID3D12GraphicsCommandList*)pNativeObject,
-            resource,
-            pUploadResource,
-            offset,
-            0,
-            (uint)subresources.Length,
-            d3d12Subresources);
-    }
-
-    public void CopyBuffer(Handle<RHI.GPUBuffer> dst, Handle<RHI.GPUBuffer> src, ulong dstOffset = 0, ulong srcOffset = 0, ulong numBytes = 0)
-    {
-        AssertNotDisposed();
-        ThrowIfNotRecording();
-#if !DEBUG
-        if (_lastError.Status != Error.None)
-        {
-            return;
-        }
-#endif
         if (dst == src)
         {
             return;
@@ -971,6 +882,48 @@ internal unsafe class D3D12CommandBuffer : D3D12Object<ID3D12GraphicsCommandList
         }
     }
 
+    public void UpdateSubResources(Handle<GPUResource> resource, Handle<GPUResource> intermediate, params ReadOnlySpan<SubResourceData> subResources)
+    {
+        AssertNotDisposed();
+        ThrowIfNotRecording();
+#if !DEBUG
+        if (_lastError.Status != Error.None)
+        {
+            return;
+        }
+#endif
+
+        IncrementCommandCount();
+
+        var d3d12Resource = _resourceDatabase.GetResource(resource);
+        var d3d12Intermediate = _resourceDatabase.GetResource(intermediate);
+        if (d3d12Intermediate == null || d3d12Resource == null)
+        {
+            RecordError(nameof(UpdateSubResources), Error.InvalidArgument);
+            return;
+        }
+
+        var d3d12Subresources = stackalloc D3D12_SUBRESOURCE_DATA[subResources.Length];
+        for (var i = 0; i < subResources.Length; i++)
+        {
+            d3d12Subresources[i] = new D3D12_SUBRESOURCE_DATA
+            {
+                pData = subResources[i].pData,
+                RowPitch = (nint)subResources[i].rowPitch,
+                SlicePitch = (nint)subResources[i].slicePitch
+            };
+        }
+
+        UpdateSubresources(
+            (ID3D12GraphicsCommandList*)pNativeObject,
+            d3d12Resource,
+            d3d12Intermediate,
+            0,
+            0,
+            (uint)subResources.Length,
+            d3d12Subresources);
+    }
+
     private D3D12_TEXTURE_COPY_LOCATION GetTextureCopyLocation(SharedPtr<ID3D12Resource> texture, TextureSubresource subres)
     {
         var flatIndex = subres.MipLevel + subres.ArrayLayer * texture.Get()->GetDesc().MipLevels;

src/Runtime/Ghost.Graphics.D3D12/D3D12GraphicsEngine.cs

@@ -75,7 +75,7 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
     private readonly Queue<ICommandBuffer> _commandBufferPool;
     private readonly Queue<CommandBufferReturnEntry> _commandBufferReturnQueue;
 
-    private ulong _currentFrame;
+    private ulong _cpuFrame;
     private bool _disposed;
 
     public IRenderDevice Device => _device;
@@ -147,7 +147,7 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
 
     public void ReturnPooledCommandBuffer(ICommandBuffer commandBuffer)
     {
-        _commandBufferReturnQueue.Enqueue(new CommandBufferReturnEntry(commandBuffer, _currentFrame));
+        _commandBufferReturnQueue.Enqueue(new CommandBufferReturnEntry(commandBuffer, _cpuFrame));
     }
 
     public ISwapChain CreateSwapChain(SwapChainDesc desc)
@@ -156,22 +156,22 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
         return new DXGISwapChain(_resourceDatabase, _descriptorAllocator, _device, desc, _desc.FrameBufferCount);
     }
 
-    public Result BeginFrame(ulong currentFrame)
+    public Result BeginFrame(ulong cpuFrame)
     {
         ThrowIfDisposed();
 
-        _currentFrame = currentFrame;
+        _cpuFrame = cpuFrame;
-        _resourceDatabase.BeginFrame(currentFrame);
+        _resourceDatabase.BeginFrame(cpuFrame);
         return Result.Success();
     }
 
-    public Result EndFrame(ulong completedFrame)
+    public Result EndFrame(ulong gpuFrame)
     {
         ThrowIfDisposed();
 
-        _resourceDatabase.EndFrame(completedFrame);
+        _resourceDatabase.EndFrame(gpuFrame);
 
-        while (_commandBufferReturnQueue.TryPeek(out var entry) && entry.returnFrame <= completedFrame)
+        while (_commandBufferReturnQueue.TryPeek(out var entry) && entry.returnFrame <= gpuFrame)
         {
             _commandBufferPool.Enqueue(entry.commandBuffer);
             _commandBufferReturnQueue.Dequeue();

src/Runtime/Ghost.Graphics.D3D12/D3D12RenderDevice.cs

@@ -1,3 +1,4 @@
+using Ghost.Core;
 using Ghost.Graphics.D3D12.Utilities;
 using Ghost.Graphics.RHI;
 using Misaki.HighPerformance.LowLevel;

src/Runtime/Ghost.Graphics.D3D12/D3D12ResourceAllocator.cs

@@ -462,10 +462,6 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
     private readonly D3D12ResourceDatabase _resourceDatabase;
     private readonly D3D12PipelineLibrary _pipelineLibrary;
 
-    // TODO: We should use ring buffer pool in d3d12ma for upload buffer.
-    private readonly Handle<RHI.GPUBuffer> _uploadBatch;
-    private ulong _uploadBatchOffset;
-
     private bool _disposed;
 
     public D3D12ResourceAllocator(
@@ -489,17 +485,6 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         _descriptorAllocator = descriptorAllocator;
         _resourceDatabase = resourceDatabase;
         _pipelineLibrary = pipelineLibrary;
-
-        // Create an upload batch
-        var uploadDesc = new BufferDesc
-        {
-            Size = _UPLOAD_BATCH_SIZE,
-            Usage = BufferUsage.Upload,
-            MemoryType = ResourceMemoryType.Upload,
-        };
-
-        _uploadBatch = CreateBuffer(in uploadDesc, "D3D12ResourceAllocator_UploadBatch");
-        _uploadBatchOffset = 0;
     }
 
     ~D3D12ResourceAllocator()
@@ -507,18 +492,6 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         Dispose();
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private Handle<GPUResource> TrackAllocation(D3D12MA_Allocation* allocation, ResourceBarrierData barrierData, ResourceViewGroup resourceDescriptor, ResourceDesc desc, string name, bool isTemp)
-    {
-        var handle = _resourceDatabase.AddAllocation(allocation, barrierData, resourceDescriptor, desc, name);
-        if (isTemp)
-        {
-            _resourceDatabase.ReleaseResource(handle);
-        }
-
-        return handle;
-    }
-
     private HRESULT CreateResource(D3D12MA_ALLOCATION_DESC* pAllocationDesc, D3D12_RESOURCE_DESC* pResourceDesc, D3D12_RESOURCE_STATES initialState, CreationOptions options, Guid* riid, void** ppv)
     {
         HRESULT hr;
@@ -563,27 +536,13 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         };
     }
 
-    public Handle<GPUResource> Allocate(ref readonly AllocationDesc desc, string name)
+    public Handle<GPUResource> Allocate(ref readonly AllocationDesc desc, string? name = null)
     {
         var allocDesc = new D3D12MA_ALLOCATION_DESC
         {
-            HeapType = desc.HeapType switch
+            HeapType = desc.HeapType.ToD3D12HeapType(),
-            {
-                HeapType.Default => D3D12_HEAP_TYPE_DEFAULT,
-                HeapType.Upload => D3D12_HEAP_TYPE_UPLOAD,
-                HeapType.Readback => D3D12_HEAP_TYPE_READBACK,
-                _ => D3D12_HEAP_TYPE_DEFAULT
-            },
             Flags = D3D12MA_ALLOCATION_FLAG_COMMITTED,
-            ExtraHeapFlags = desc.HeapFlags switch
+            ExtraHeapFlags = desc.HeapFlags.ToD3D12HeapFlags()
-            {
-                HeapFlags.None => D3D12_HEAP_FLAG_NONE,
-                HeapFlags.AllowBuffers => D3D12_HEAP_FLAG_ALLOW_ONLY_BUFFERS,
-                HeapFlags.AllowTextures => D3D12_HEAP_FLAG_ALLOW_ONLY_NON_RT_DS_TEXTURES,
-                HeapFlags.AllowRTAndDS => D3D12_HEAP_FLAG_ALLOW_ONLY_RT_DS_TEXTURES,
-                HeapFlags.AlowBufferAndTexture => D3D12_HEAP_FLAG_ALLOW_ALL_BUFFERS_AND_TEXTURES,
-                _ => D3D12_HEAP_FLAG_NONE
-            }
         };
 
         // SizeInBytes must be aligned to 64KB for committed resources
@@ -606,10 +565,10 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             sync = BarrierSync.None
         };
 
-        return TrackAllocation(alloc, barrierData, ResourceViewGroup.Invalid, default, name, false);
+        return _resourceDatabase.AddAllocation(alloc, barrierData, ResourceViewGroup.Invalid, default, name);
     }
 
-    public Handle<GPUTexture> CreateTexture(ref readonly TextureDesc desc, string name, CreationOptions options = default)
+    public Handle<GPUTexture> CreateTexture(ref readonly TextureDesc desc, string? name = null, CreationOptions options = default)
     {
         Debug.Assert(!_disposed);
 
@@ -634,8 +593,11 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         else
         {
             hr = CreateResource(&allocationDesc, &resourceDesc, D3D12_RESOURCE_STATE_COMMON, options, null, (void**)&pAllocation);
+            if (hr.SUCCEEDED)
+            {
                 pResource = pAllocation->GetResource();
             }
+        }
 
         if (hr.FAILED)
         {
@@ -645,7 +607,6 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             return Handle<GPUTexture>.Invalid;
         }
 
-        var isTemp = options.AllocationType == ResourceAllocationType.Temporary;
         var resourceDescriptor = ResourceViewGroup.Invalid;
         if (desc.Usage.HasFlag(TextureUsage.ShaderResource))
         {
@@ -701,13 +662,13 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         }
         else
         {
-            resource = TrackAllocation(pAllocation, barrierData, resourceDescriptor, ResourceDesc.Texture(desc), name, isTemp);
+            resource = _resourceDatabase.AddAllocation(pAllocation, barrierData, resourceDescriptor, ResourceDesc.Texture(desc), name);
         }
 
         return resource.AsTexture();
     }
 
-    public Handle<GPUTexture> CreateRenderTarget(ref readonly RenderTargetDesc desc, string name, CreationOptions options = default)
+    public Handle<GPUTexture> CreateRenderTarget(ref readonly RenderTargetDesc desc, string? name = null, CreationOptions options = default)
     {
         Debug.Assert(!_disposed);
 
@@ -715,7 +676,7 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         return CreateTexture(in textureDesc, name, options);
     }
 
-    public Handle<RHI.GPUBuffer> CreateBuffer(ref readonly BufferDesc desc, string name, CreationOptions options = default)
+    public Handle<GPUBuffer> CreateBuffer(ref readonly BufferDesc desc, string? name = null, CreationOptions options = default)
     {
         Debug.Assert(!_disposed);
         CheckBufferSize(desc.Size);
@@ -760,10 +721,9 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
 #if DEBUG
             ThrowIfFailed(hr);
 #endif
-            return Handle<RHI.GPUBuffer>.Invalid;
+            return Handle<GPUBuffer>.Invalid;
         }
 
-        var isTemp = options.AllocationType == ResourceAllocationType.Temporary;
         var resourceDescriptor = ResourceViewGroup.Invalid;
 
         if (desc.Usage.HasFlag(BufferUsage.Constant))
@@ -814,40 +774,10 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         }
         else
         {
-            resource = TrackAllocation(pAllocation, barrierData, resourceDescriptor, ResourceDesc.Buffer(desc), name, isTemp);
+            resource = _resourceDatabase.AddAllocation(pAllocation, barrierData, resourceDescriptor, ResourceDesc.Buffer(desc), name);
         }
 
-        return resource.AsGraphicsBuffer();
+        return resource.AsBuffer();
-    }
-
-    public Handle<RHI.GPUBuffer> CreateTempUploadBuffer(ulong sizeInBytes, out ulong offset)
-    {
-        if (sizeInBytes <= _MAX_RESOURCE_SIZE_TO_FIT_IN_UPLOAD_BATCH && sizeInBytes + _uploadBatchOffset <= _UPLOAD_BATCH_SIZE)
-        {
-            offset = _uploadBatchOffset;
-            _uploadBatchOffset += sizeInBytes;
-            return _uploadBatch;
-        }
-        else
-        {
-            var bufferDesc = new BufferDesc
-            {
-                Size = (uint)sizeInBytes,
-                Usage = BufferUsage.Upload,
-                MemoryType = ResourceMemoryType.Upload,
-            };
-
-            var options = new CreationOptions
-            {
-                AllocationType = ResourceAllocationType.Temporary,
-            };
-
-            offset = 0;
-            var handle = CreateBuffer(in bufferDesc, "TempUploadBuffer", options);
-
-            _resourceDatabase.ReleaseResource(handle.AsResource());
-            return handle;
-        }
     }
 
     public Identifier<Sampler> CreateSampler(ref readonly SamplerDesc desc)
@@ -887,7 +817,6 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             return;
         }
 
-        _resourceDatabase.ReleaseResourceImmediately(_uploadBatch.AsResource());
         _d3d12MA.Dispose();
 
         _disposed = true;

src/Runtime/Ghost.Graphics.D3D12/D3D12ResourceDatabase.cs

@@ -4,14 +4,14 @@ using Ghost.Graphics.RHI;
 using Misaki.HighPerformance.LowLevel;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
+using Misaki.HighPerformance.LowLevel.Utilities;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
 using TerraFX.Interop.DirectX;
 
 namespace Ghost.Graphics.D3D12;
 
-// TODO: Thread safety
+internal unsafe class D3D12ResourceDatabase : IResourceDatabase
-internal class D3D12ResourceDatabase : IResourceDatabase
 {
     internal unsafe record struct ResourceRecord
     {
@@ -109,7 +109,7 @@ internal class D3D12ResourceDatabase : IResourceDatabase
 
     private int _writeLock;
 
-    private ulong _currentFrame;
+    private ulong _cpuFrame;
     private bool _disposed;
 
     public D3D12ResourceDatabase(D3D12DescriptorAllocator descriptorAllocator)
@@ -323,12 +323,12 @@ internal class D3D12ResourceDatabase : IResourceDatabase
     {
         Debug.Assert(!_disposed);
 
-        if (_resources.TryGetElementAt(handle.ID, handle.Generation, out var record))
+        if (!_resources.TryGetElementAt(handle.ID, handle.Generation, out var record))
         {
             return;
         }
 
-        var entry = new ReleaseEntry(record, _currentFrame);
+        var entry = new ReleaseEntry(record, _cpuFrame);
 
         _releaseQueue.Enqueue(entry);
         _resources.Remove(handle.ID, handle.Generation);
@@ -399,20 +399,52 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         return Error.None;
     }
 
-    public void BeginFrame(ulong currentFrame)
+    public Error Map(Handle<GPUResource> handle, uint subResource, ResourceRange? readRange, ResourceRange? writeRange, void* pData, nuint size)
     {
-        Debug.Assert(!_disposed);
+        var r = GetResourceRecord(handle);
-        _currentFrame = currentFrame;
+        if (r.IsFailure)
+        {
+            return r.Error;
         }
 
-    public void EndFrame(ulong completedFrame)
+        var resource = r.Value.ResourcePtr;
+
+        var rRange = readRange.HasValue ? new D3D12_RANGE { Begin = readRange.Value.Start, End = readRange.Value.End } : default;
+        var wRange = writeRange.HasValue ? new D3D12_RANGE { Begin = writeRange.Value.Start, End = writeRange.Value.End } : default;
+
+        void * mappedData = null;
+        resource.Get()->Map(subResource, readRange.HasValue ? &rRange : null, &mappedData);
+        MemoryUtility.MemCpy(mappedData, pData, size);
+        resource.Get()->Unmap(subResource, writeRange.HasValue ? &wRange : null);
+
+        return Error.None;
+    }
+
+    public ulong GetIntermediateResourceSize(Handle<GPUResource> resource, uint firstSubResource, uint numSubResources)
+    {
+        var r = GetResourceRecord(resource);
+        if (r.IsFailure)
+        {
+            return 0;
+        }
+
+        return GetRequiredIntermediateSize(r.Value.ResourcePtr.Get(), firstSubResource, numSubResources);
+    }
+
+    public void BeginFrame(ulong cpuFrame)
+    {
+        Debug.Assert(!_disposed);
+        _cpuFrame = cpuFrame;
+    }
+
+    public void EndFrame(ulong gpuFrame)
     {
         Debug.Assert(!_disposed);
 
         while (_releaseQueue.Count > 0)
         {
             var toRelease = _releaseQueue.Peek();
-            if (toRelease.fenceValue > completedFrame)
+            if (toRelease.fenceValue > gpuFrame)
             {
                 break;
             }
@@ -431,6 +463,8 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         {
             record.Release(_descriptorAllocator);
         }
+
+        _resources.Clear();
     }
 
     public void Dispose()

src/Runtime/Ghost.Graphics.D3D12/Utilities/D3D12Utility.cs

@@ -386,6 +386,31 @@ internal static unsafe class D3D12Utility
         return flags;
     }
 
+    public static D3D12_HEAP_TYPE ToD3D12HeapType(this HeapType heapType)
+    {
+        return heapType switch
+        {
+            HeapType.Default => D3D12_HEAP_TYPE_DEFAULT,
+            HeapType.Upload => D3D12_HEAP_TYPE_UPLOAD,
+            HeapType.Readback => D3D12_HEAP_TYPE_READBACK,
+            _ => throw new ArgumentException($"Unknown heap type: {heapType}")
+        };
+    }
+
+    public static D3D12_HEAP_FLAGS ToD3D12HeapFlags(this HeapFlags flags)
+    {
+        return flags switch
+        {
+            HeapFlags.None => D3D12_HEAP_FLAG_NONE,
+            HeapFlags.Shared => D3D12_HEAP_FLAG_SHARED,
+            HeapFlags.AllowOnlyBuffers => D3D12_HEAP_FLAG_ALLOW_ONLY_BUFFERS,
+            HeapFlags.AllowOnlyTextures => D3D12_HEAP_FLAG_ALLOW_ONLY_NON_RT_DS_TEXTURES,
+            HeapFlags.AllowOnlyRTAndDS => D3D12_HEAP_FLAG_ALLOW_ONLY_RT_DS_TEXTURES,
+            HeapFlags.AllowAllBufferAndTexture => D3D12_HEAP_FLAG_ALLOW_ALL_BUFFERS_AND_TEXTURES,
+            _ => throw new ArgumentException($"Unknown heap flags: {flags}")
+        };
+    }
+
     public static D3D12_RESOURCE_DESC ToD3D12ResourceDesc(this in TextureDesc desc)
     {
         var dxgiFormat = desc.Format.ToDXGIFormat();

src/Runtime/Ghost.Graphics.RHI/Common.cs

@@ -152,6 +152,19 @@ public record struct Vertex
     public float2 uv;
 }
 
+public struct ResourceRange
+{
+    public nuint Start
+    {
+        get; set;
+    }
+
+    public nuint End
+    {
+        get; set;
+    }
+}
+
 public readonly struct ShaderVariant;
 public readonly struct GraphicsPipeline;
 

src/Runtime/Ghost.Graphics.RHI/ICommandBuffer.cs

@@ -185,24 +185,6 @@ public interface ICommandBuffer : IDisposable
     // TODO: This method is not supported yet.
     void DispatchRay();
 
-    /// <summary>
-    /// Uploads the specified data to the buffer represented by the given handle.
-    /// </summary>
-    /// <typeparam name="T">The unmanaged Value space of the elements to upload to the buffer.</typeparam>
-    /// <param name="buffer">A handle to the buffer that will receive the uploaded data.</param>
-    /// <param name="data">A read-only span containing the data to upload to the buffer. The span must contain elements of space
-    /// <typeparamref name="T"/>.</param>
-    void UploadBuffer<T>(Handle<GPUBuffer> buffer, params ReadOnlySpan<T> data)
-        where T : unmanaged;
-
-    /// <summary>
-    /// Uploads texture data to the specified texture resource starting at the given subresource index.
-    /// </summary>
-    /// <param name="texture">The texture resource to which the subresource data will be uploaded. Must be a valid, initialized texture handle.</param>
-    /// <param name="subresources">A reference to the structure containing the subresource data to upload. The data must match the Format and layout expected by the texture.</param>
-    /// Must be greater than zero and not exceed the remaining subresources in the texture.</param>
-    void UploadTexture(Handle<GPUTexture> texture, params ReadOnlySpan<SubResourceData> subresources);
-
     /// <summary>
     /// Copies a specified number of bytes from the source graphics buffer to the destination graphics buffer.
     /// </summary>
@@ -221,4 +203,6 @@ public interface ICommandBuffer : IDisposable
     /// <param name="src">The handle to the source texture from which data will be read.</param>
     /// <param name="srcRegion">The region of the source texture to copy from. If null, the entire texture will be used.</param>
     void CopyTexture(Handle<GPUTexture> dst, TextureRegion? dstRegion, Handle<GPUTexture> src, TextureRegion? srcRegion);
+
+    void UpdateSubResources(Handle<GPUResource> resource, Handle<GPUResource> intermediate, params ReadOnlySpan<SubResourceData> subResources);
 }

src/Runtime/Ghost.Graphics.RHI/IGraphicsEngine.cs

@@ -74,14 +74,14 @@ public interface IGraphicsEngine : IDisposable
     /// <summary>
     /// Begin the current frame.
     /// </summary>
-    /// <param name="currentFrame">CPU fence value for synchronization</param>
+    /// <param name="cpuFrame">CPU fence value for synchronization</param>
     /// <returns>Result of the begin frame operation</returns>
-    Result BeginFrame(ulong currentFrame);
+    Result BeginFrame(ulong cpuFrame);
 
     /// <summary>
     /// End the current frame.
     /// </summary>
-    /// <param name="completedFrame">GPU fence value for synchronization</param>
+    /// <param name="gpuFrame">GPU fence value for synchronization</param>
     /// <returns>Result of the end frame operation</returns>
-    Result EndFrame(ulong completedFrame);
+    Result EndFrame(ulong gpuFrame);
 }

src/Runtime/Ghost.Graphics.RHI/IRenderDevice.cs

@@ -1,3 +1,5 @@
+using Ghost.Core;
+
 namespace Ghost.Graphics.RHI;
 
 [Flags]

src/Runtime/Ghost.Graphics.RHI/IResourceAllocator.cs

@@ -5,7 +5,6 @@ namespace Ghost.Graphics.RHI;
 public enum ResourceAllocationType
 {
     Default,
-    Temporary,
     Suballocation,
 }
 
@@ -36,11 +35,12 @@ public enum HeapType
 
 public enum HeapFlags
 {
-    None = 0,
+    None,
-    AllowBuffers,
+    Shared,
-    AllowTextures,
+    AllowOnlyBuffers,
-    AllowRTAndDS,
+    AllowOnlyTextures,
-    AlowBufferAndTexture,
+    AllowOnlyRTAndDS,
+    AllowAllBufferAndTexture,
 }
 
 public struct AllocationDesc
@@ -89,7 +89,7 @@ public interface IResourceAllocator : IDisposable
     /// <param name="desc">Allocation description</param>
     /// <param name="name">Debug name of the allocation</param>
     /// <returns>An <see cref="Handle{GPUResource}"/> point to the allocated memory</returns>
-    Handle<GPUResource> Allocate(ref readonly AllocationDesc desc, string name);
+    Handle<GPUResource> Allocate(ref readonly AllocationDesc desc, string? name = null);
 
     /// <summary>
     /// Creates a texture resource
@@ -98,7 +98,7 @@ public interface IResourceAllocator : IDisposable
     /// <param name="name">Debug name of the resource</param>
     /// <param name="options">Additional options of the resource allocation</param>
     /// <returns>An <see cref="Handle{Texture}"/> point to the resource</returns>
-    Handle<GPUTexture> CreateTexture(ref readonly TextureDesc desc, string name, CreationOptions options = default);
+    Handle<GPUTexture> CreateTexture(ref readonly TextureDesc desc, string? name = null, CreationOptions options = default);
 
     /// <summary>
     /// Creates a render Target for off-screen rendering
@@ -107,7 +107,7 @@ public interface IResourceAllocator : IDisposable
     /// <param name="name">Debug name of the resource</param>
     /// <param name="options">Additional options of the resource allocation</param>
     /// <returns>An <see cref="Handle{Texture}"/> point to the resource</returns>
-    Handle<GPUTexture> CreateRenderTarget(ref readonly RenderTargetDesc desc, string name, CreationOptions options = default);
+    Handle<GPUTexture> CreateRenderTarget(ref readonly RenderTargetDesc desc, string? name = null, CreationOptions options = default);
 
     /// <summary>
     /// Creates a buffer resource
@@ -116,18 +116,7 @@ public interface IResourceAllocator : IDisposable
     /// <param name="name">Debug name of the resource</param>
     /// <param name="options">Additional options of the resource allocation</param>
     /// <returns>An <see cref="Handle{GraphicsBuffer}"/> point to the resource</returns>
-    Handle<GPUBuffer> CreateBuffer(ref readonly BufferDesc desc, string name, CreationOptions options = default);
+    Handle<GPUBuffer> CreateBuffer(ref readonly BufferDesc desc, string? name = null, CreationOptions options = default);
-
-    /// <summary>
-    /// Creates a temporary upload buffer of the specified size in bytes.
-    /// </summary>
-    /// <remarks>
-    /// This method has been optimized for frequent calls during frame updates. It efficiently manages memory to minimize fragmentation and overhead.
-    /// </remarks>
-    /// <param name="sizeInBytes">The size of the upload buffer to create, in bytes.</param>
-    /// <param name="offset">The offset within the upload buffer where the allocation begins.</param>
-    /// <returns>An <see cref="Handle{GraphicsBuffer}"/> pointing to the created upload buffer.</returns>
-    Handle<GPUBuffer> CreateTempUploadBuffer(ulong sizeInBytes, out ulong offset);
 
     /// <summary>
     /// Creates a new sampler object using the specified sampler description.

src/Runtime/Ghost.Graphics.RHI/IResourceDatabase.cs

@@ -31,22 +31,8 @@ public enum BindlessAccess
     UnorderedAccess,
 }
 
-// TODO: Consider adding methods for resource enumeration, statistics, and bulk operations.
+public unsafe interface IResourceDatabase : IDisposable
-// TODO: Consider adding async resource loading and streaming support.
-public interface IResourceDatabase : IDisposable
 {
-    /*
-    /// <summary>
-    /// Imports an external unmanaged resource and returns a handle for use within the resource management system.
-    /// </summary>
-    /// <typeparam name="T">The space of the unmanaged resource pointer to import.</typeparam>
-    /// <param name="resourcePtr">A pointer to the external unmanaged resource to be imported. Must remain valid for the duration of the resource's usage.</param>
-    /// <param name="initialState">The initial state to assign to the imported resource.</param>
-    /// <returns>A handle representing the imported resource, which can be used for subsequent operations.</returns>
-    unsafe Handle<GPUResource> ImportExternalResource<T>(T resourcePtr, ResourceState initialState, string? name = null)
-        where T : unmanaged;
-    */
-
     void EnterParallelRead();
 
     void ExitParallelRead();
@@ -139,4 +125,8 @@ public interface IResourceDatabase : IDisposable
     /// <param name="handleB">The second handle whose associated resource is to be swapped.</param>
     /// <returns>An Error indicating the success or failure of the swap operation.</returns>
     Error Swap(Handle<GPUResource> handleA, Handle<GPUResource> handleB);
+
+    Error Map(Handle<GPUResource> handle, uint subResource, ResourceRange? readRange, ResourceRange? writeRange, void* pData, nuint size);
+
+    ulong GetIntermediateResourceSize(Handle<GPUResource> resource, uint firstSubResource, uint numSubResources);
 }

src/Runtime/Ghost.Graphics.RHI/ISwapChain.cs

@@ -48,7 +48,7 @@ public interface ISwapChain : IDisposable
     /// <summary>
     /// Gets all back buffer textures
     /// </summary>
-    /// <returns>AlowBufferAndTexture back buffer textures</returns>
+    /// <returns>AllowAllBufferAndTexture back buffer textures</returns>
     ReadOnlySpan<Handle<GPUTexture>> GetBackBuffers();
 
     /// <summary>

src/Runtime/Ghost.Graphics.RHI/ResourceHandle.cs

@@ -25,7 +25,7 @@ public static class ResourceHandleExtensions
         return new Handle<GPUTexture>(resource.ID, resource.Generation);
     }
 
-    public static Handle<GPUBuffer> AsGraphicsBuffer(this Handle<GPUResource> resource)
+    public static Handle<GPUBuffer> AsBuffer(this Handle<GPUResource> resource)
     {
         return new Handle<GPUBuffer>(resource.ID, resource.Generation);
     }

src/Runtime/Ghost.Graphics/Core/Material.cs

@@ -11,16 +11,16 @@ namespace Ghost.Graphics.Core;
 internal struct CBufferCache : IResourceReleasable
 {
     private UnsafeArray<byte> _cpuData;
-    private Handle<RHI.GPUBuffer> _gpuResource;
+    private Handle<GPUBuffer> _gpuResource;
     private uint _size;
 
     public readonly UnsafeArray<byte> CpuData => _cpuData;
-    public readonly Handle<RHI.GPUBuffer> GpuResource => _gpuResource;
+    public readonly Handle<GPUBuffer> GpuResource => _gpuResource;
     public readonly uint Size => _size;
 
     public readonly bool IsCreated => _size != 0 && _gpuResource.IsValid && _cpuData.IsCreated;
 
-    public CBufferCache(Handle<RHI.GPUBuffer> buffer, uint bufferSize)
+    public CBufferCache(Handle<GPUBuffer> buffer, uint bufferSize)
     {
         _size = bufferSize;
         _cpuData = new UnsafeArray<byte>((int)bufferSize, Allocator.Persistent);
@@ -37,7 +37,7 @@ internal struct CBufferCache : IResourceReleasable
         _cpuData.Dispose();
         database.ReleaseResource(_gpuResource.AsResource());
 
-        _gpuResource = Handle<RHI.GPUBuffer>.Invalid;
+        _gpuResource = Handle<GPUBuffer>.Invalid;
         _size = 0;
     }
 }

src/Runtime/Ghost.Graphics/Core/Mesh.cs

@@ -1,7 +1,6 @@
 using Ghost.Core;
 using Ghost.Graphics.RHI;
 using Ghost.Graphics.Utilities;
-using Misaki.HighPerformance.Jobs;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
 using Misaki.HighPerformance.Mathematics;
@@ -138,7 +137,7 @@ public struct Mesh : IResourceReleasable
     /// <summary>
     /// Gets the handle to the vertex buffer on the GPU.
     /// </summary>
-    public Handle<RHI.GPUBuffer> VertexBuffer
+    public Handle<GPUBuffer> VertexBuffer
     {
         get; internal set;
     }
@@ -146,7 +145,7 @@ public struct Mesh : IResourceReleasable
     /// <summary>
     /// Gets the handle to the index buffer on the GPU.
     /// </summary>
-    public Handle<RHI.GPUBuffer> IndexBuffer
+    public Handle<GPUBuffer> IndexBuffer
     {
         get; internal set;
     }
@@ -154,7 +153,7 @@ public struct Mesh : IResourceReleasable
     /// <summary>
     /// Gets the handle to the meshlet buffer on the GPU.
     /// </summary>
-    public Handle<RHI.GPUBuffer> MeshLetBuffer
+    public Handle<GPUBuffer> MeshLetBuffer
     {
         get; internal set;
     }
@@ -162,7 +161,7 @@ public struct Mesh : IResourceReleasable
     /// <summary>
     /// Gets the handle to the meshlet vertices buffer on the GPU.
     /// </summary>
-    public Handle<RHI.GPUBuffer> MeshletVerticesBuffer
+    public Handle<GPUBuffer> MeshletVerticesBuffer
     {
         get; internal set;
     }
@@ -170,7 +169,7 @@ public struct Mesh : IResourceReleasable
     /// <summary>
     /// Gets the handle to the meshlet triangles buffer on the GPU.
     /// </summary>
-    public Handle<RHI.GPUBuffer> MeshletTrianglesBuffer
+    public Handle<GPUBuffer> MeshletTrianglesBuffer
     {
         get; internal set;
     }
@@ -178,12 +177,12 @@ public struct Mesh : IResourceReleasable
     /// <summary>
     /// Gets the handle to the mesh data buffer on the GPU.
     /// </summary>
-    public Handle<RHI.GPUBuffer> ObjectDataBuffer
+    public Handle<GPUBuffer> ObjectDataBuffer
     {
         get; internal set;
     }
 
-    internal Mesh(ReadOnlySpan<Vertex> vertices, ReadOnlySpan<uint> indices, Handle<RHI.GPUBuffer> vertexBuffer, Handle<RHI.GPUBuffer> indexBuffer)
+    internal Mesh(ReadOnlySpan<Vertex> vertices, ReadOnlySpan<uint> indices, Handle<GPUBuffer> vertexBuffer, Handle<GPUBuffer> indexBuffer)
     {
         Vertices = new UnsafeList<Vertex>(vertices.Length, Allocator.Persistent);
         Indices = new UnsafeList<uint>(indices.Length, Allocator.Persistent);

src/Runtime/Ghost.Graphics/Core/RenderingContext.cs

@@ -2,10 +2,11 @@ using Ghost.Core;
 using Ghost.Graphics.RHI;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
+using System.Diagnostics;
 
 namespace Ghost.Graphics.Core;
 
-// TODO: Temporary rendering context for resource creation and data upload. We will refactor it later when we have a better understanding of the engine architecture.
+// TODO: Temporary rendering context for heap creation and data upload. We will refactor it later when we have a better understanding of the engine architecture.
 public readonly unsafe ref struct RenderingContext
 {
     private readonly IGraphicsEngine _engine;
@@ -82,6 +83,49 @@ public readonly unsafe ref struct RenderingContext
         ResourceDatabase.SetResourceBarrierData(resource, new ResourceBarrierData(newLayout, newAccess, newSync));
     }
 
+    private void UploadBuffer<T>(Handle<GPUBuffer> buffer, params ReadOnlySpan<T> data)
+        where T : unmanaged
+    {
+        var r = _engine.ResourceDatabase.GetResourceDescription(buffer.AsResource());
+        if (r.IsFailure)
+        {
+            return;
+        }
+
+        Debug.Assert(r.Value.Type == ResourceType.Buffer);
+
+        var sizeInBytes = (nuint)(data.Length * sizeof(T));
+        var memoryType = r.Value.BufferDescription.MemoryType;
+
+        if (memoryType == ResourceMemoryType.Upload)
+        {
+            fixed (T* pData = data)
+            {
+                ResourceDatabase.Map(buffer.AsResource(), 0, null, null, pData, sizeInBytes);
+            }
+        }
+        else
+        {
+            //var uploadHandle = _resourceAllocator.CreateTempUploadBuffer(sizeInBytes, out var offset);
+            //var uploadResource = _resourceDatabase.GetResource(uploadHandle.AsResource());
+            var uploadDesc = new BufferDesc
+            {
+                Size = sizeInBytes,
+                Usage = BufferUsage.Upload,
+                MemoryType = ResourceMemoryType.Upload,
+            };
+
+            var uploadHandle = _resourceManager.CreateTransientBuffer(in uploadDesc);
+
+            fixed (T* pData = data)
+            {
+                ResourceDatabase.Map(uploadHandle.AsResource(), 0, null, null, pData, sizeInBytes);
+            }
+
+            _directCmd.CopyBuffer(buffer, uploadHandle, 0, 0, sizeInBytes);
+        }
+    }
+
     public Handle<Mesh> CreateMesh(UnsafeList<Vertex> vertices, UnsafeList<uint> indices, bool staticMesh)
     {
         var mesh = _resourceManager.CreateMesh(vertices, indices);
@@ -98,8 +142,8 @@ public readonly unsafe ref struct RenderingContext
         TransitionBarrier(vertexHandle, false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
         TransitionBarrier(indexHandle, false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
 
-        _directCmd.UploadBuffer(meshData.VertexBuffer, meshData.Vertices.AsSpan());
+        UploadBuffer(meshData.VertexBuffer, meshData.Vertices.AsSpan());
-        _directCmd.UploadBuffer(meshData.IndexBuffer, meshData.Indices.AsSpan());
+        UploadBuffer(meshData.IndexBuffer, meshData.Indices.AsSpan());
 
         TransitionBarrier(vertexHandle, false, BarrierLayout.Undefined, BarrierAccess.ShaderResource, BarrierSync.VertexShading);
         TransitionBarrier(indexHandle, false, BarrierLayout.Undefined, BarrierAccess.IndexBuffer, BarrierSync.IndexInput);
@@ -147,8 +191,8 @@ public readonly unsafe ref struct RenderingContext
         TransitionBarrier(vertexHandle, false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
         TransitionBarrier(indexHandle, false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
 
-        _directCmd.UploadBuffer(meshRef.VertexBuffer, meshRef.Vertices.AsSpan());
+        UploadBuffer(meshRef.VertexBuffer, meshRef.Vertices.AsSpan());
-        _directCmd.UploadBuffer(meshRef.IndexBuffer, meshRef.Indices.AsSpan());
+        UploadBuffer(meshRef.IndexBuffer, meshRef.Indices.AsSpan());
 
         TransitionBarrier(vertexHandle, false, BarrierLayout.Undefined, BarrierAccess.ShaderResource, BarrierSync.VertexShading);
         TransitionBarrier(indexHandle, false, BarrierLayout.Undefined, BarrierAccess.IndexBuffer, BarrierSync.IndexInput);
@@ -204,9 +248,9 @@ public readonly unsafe ref struct RenderingContext
         TransitionBarrier(meshRef.MeshletVerticesBuffer.AsResource(), false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
         TransitionBarrier(meshRef.MeshletTrianglesBuffer.AsResource(), false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
 
-        _directCmd.UploadBuffer(meshRef.MeshLetBuffer, meshletData.meshlets.AsSpan());
+        UploadBuffer(meshRef.MeshLetBuffer, meshletData.meshlets.AsSpan());
-        _directCmd.UploadBuffer(meshRef.MeshletVerticesBuffer, meshletData.meshletVertices.AsSpan());
+        UploadBuffer(meshRef.MeshletVerticesBuffer, meshletData.meshletVertices.AsSpan());
-        _directCmd.UploadBuffer(meshRef.MeshletTrianglesBuffer, meshletData.meshletTriangles.AsSpan());
+        UploadBuffer(meshRef.MeshletTrianglesBuffer, meshletData.meshletTriangles.AsSpan());
 
         TransitionBarrier(meshRef.MeshLetBuffer.AsResource(), false, BarrierLayout.Undefined, BarrierAccess.ShaderResource, BarrierSync.NonPixelShading | BarrierSync.PixelShading);
         TransitionBarrier(meshRef.MeshletVerticesBuffer.AsResource(), false, BarrierLayout.Undefined, BarrierAccess.ShaderResource, BarrierSync.NonPixelShading | BarrierSync.PixelShading);
@@ -236,7 +280,7 @@ public readonly unsafe ref struct RenderingContext
         var bufferHandle = meshData.ObjectDataBuffer.AsResource();
 
         TransitionBarrier(bufferHandle, false, BarrierLayout.Undefined, BarrierAccess.CopyDest, BarrierSync.Copy);
-        _directCmd.UploadBuffer(meshData.ObjectDataBuffer, data);
+        UploadBuffer(meshData.ObjectDataBuffer, data);
         TransitionBarrier(bufferHandle, false, BarrierLayout.Undefined, BarrierAccess.ShaderResource, BarrierSync.PixelShading | BarrierSync.NonPixelShading);
     }
 
@@ -252,16 +296,29 @@ public readonly unsafe ref struct RenderingContext
     public void UploadTexture<T>(Handle<GPUTexture> texture, ReadOnlySpan<T> data)
         where T : unmanaged
     {
-        var desc = ResourceDatabase.GetResourceDescription(texture.AsResource()).GetValueOrThrow();
-
         //var size = ResourceAllocator.GetSizeInfo(desc).Size;
         //if ((ulong)(data.Length * sizeof(T)) != ResourceAllocator.GetSizeInfo(desc).Size)
         //{
         //    throw new ArgumentException("Data size does not match texture size.");
         //}
 
+        var desc = ResourceDatabase.GetResourceDescription(texture.AsResource()).GetValueOrThrow();
         desc.TextureDescription.Format.GetSurfaceInfo(desc.TextureDescription.Width, desc.TextureDescription.Height, out var rowPitch, out var slicePitch, out _);
 
+        var requiredSize = ResourceDatabase.GetIntermediateResourceSize(texture.AsResource(), 0, 1);
+        var uploadDesc = new BufferDesc
+        {
+            Size = requiredSize,
+            Usage = BufferUsage.Upload,
+            MemoryType = ResourceMemoryType.Upload,
+        };
+
+        var uploadHandle = _resourceManager.CreateTransientBuffer(in uploadDesc);
+        if (uploadHandle.IsInvalid)
+        {
+            throw new OutOfMemoryException("Failed to create upload buffer for texture data.");
+        }
+
         TransitionBarrier(texture.AsResource(), true, BarrierLayout.CopyDest, BarrierAccess.CopyDest, BarrierSync.Copy);
 
         fixed (T* pData = data)
@@ -273,7 +330,7 @@ public readonly unsafe ref struct RenderingContext
                 slicePitch = slicePitch
             };
 
-            _directCmd.UploadTexture(texture, subresourceData);
+            _directCmd.UpdateSubResources(texture.AsResource(), uploadHandle.AsResource(), subresourceData);
         }
     }
 }

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraph.cs

@@ -5,7 +5,7 @@ using System.Diagnostics;
 namespace Ghost.Graphics.RenderGraphModule;
 
 /// <summary>
-/// Main render graph class that manages resource allocation and pass execution.
+/// Main render graph class that manages heap allocation and pass execution.
 /// </summary>
 public sealed class RenderGraph : IDisposable
 {
@@ -125,7 +125,7 @@ public sealed class RenderGraph : IDisposable
     /// </summary>
     /// <param name="buffer">The external buffer handle.</param>
     /// <returns>The identifier of the imported render graph buffer. Invalid if import fails.</returns>
-    public Identifier<RGBuffer> ImportBuffer(Handle<RHI.GPUBuffer> buffer, string name)
+    public Identifier<RGBuffer> ImportBuffer(Handle<GPUBuffer> buffer, string name)
     {
         var r = _resourceDatabase.GetResourceDescription(buffer.AsResource());
         if (r.IsFailure)
@@ -178,7 +178,7 @@ public sealed class RenderGraph : IDisposable
     }
 
     /// <summary>
-    /// Compiles the render graph by culling unused passes and determining resource lifetimes.
+    /// Compiles the render graph by culling unused passes and determining heap lifetimes.
     /// </summary>
     public Error Compile(ViewState viewState)
     {

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphAliasing.cs

@@ -12,7 +12,7 @@ internal struct MemoryBlock
     public bool isFree;
     public int firstUsePass;
     public int lastUsePass;
-    public int logicalResourceIndex; // Which logical resource is currently using this block
+    public int logicalResourceIndex; // Which logical heap is currently using this block
 
     public MemoryBlock(ulong offset, ulong size)
     {
@@ -267,7 +267,7 @@ internal sealed class ResourceAliasingManager
 
     private readonly ResourceHeap _heap;
     private readonly List<PlacedResource> _placedResources;
-    // Mapping from logical resource index to placed resource index
+    // Mapping from logical heap index to placed heap index
     private readonly Dictionary<int, int> _logicalToPlaced;
 
     private const ulong _DEFAULT_TEXTURE_ALIGNMENT = 65536; // 64KB
@@ -373,7 +373,7 @@ internal sealed class ResourceAliasingManager
         _heap.size = peakMemoryUsage;
         _heap.Reset();
 
-        // Allocate each logical resource in the heap
+        // Allocate each logical heap in the heap
         foreach (var (logicalIndex, logicalResource) in logicalResources)
         {
             // TODO: Currently we are recalculating the aliasing candidates in the real allocation pass.
@@ -414,7 +414,7 @@ internal sealed class ResourceAliasingManager
         }
 
         // Second pass: Populate aliasedLogicalResources lists
-        // For each placed resource, find all OTHER placed resources at the same offset
+        // For each placed heap, find all OTHER placed resources at the same offset
         for (var i = 0; i < _placedResources.Count; i++)
         {
             var placed = _placedResources[i];
@@ -432,7 +432,7 @@ internal sealed class ResourceAliasingManager
                 // Check if they're at the same offset
                 if (other.heapOffset == placed.heapOffset)
                 {
-                    // Add the other's logical resource to this one's aliased list
+                    // Add the other's logical heap to this one's aliased list
                     var otherLogicalIndex = other.aliasedLogicalResources[0]; // Each has exactly one at this point
                     if (!placed.aliasedLogicalResources.Contains(otherLogicalIndex))
                     {

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphBarriers.cs

@@ -12,7 +12,7 @@ internal enum BarrierFlags
 }
 
 /// <summary>
-/// Represents a resource barrier requirement that needs to be resolved at runtime.
+/// Represents a heap barrier requirement that needs to be resolved at runtime.
 /// </summary>
 internal struct ResourceBarrier
 {
@@ -55,7 +55,7 @@ internal struct ResourceBarrier
 }
 
 /// <summary>
-/// Tracks the current state of a resource across passes during compilation.
+/// Tracks the current state of a heap across passes during compilation.
 /// </summary>
 internal sealed class ResourceStateTracker
 {
@@ -124,7 +124,7 @@ internal static class RenderGraphBarriers
     }
 
     /// <summary>
-    /// Inserts aliasing barriers when a placed resource is reused.
+    /// Inserts aliasing barriers when a placed heap is reused.
     /// </summary>
     private static void InsertAliasingBarriers(
         RenderGraphPassBase pass,
@@ -148,20 +148,20 @@ internal static class RenderGraphBarriers
                     continue;
                 }
 
-                // Check if this is the first use of this logical resource
+                // Check if this is the first use of this logical heap
                 if (resource.firstUsePass == pass.index)
                 {
-                    // Get the placed resource
+                    // Get the placed heap
                     var placedIndex = aliasingManager.GetPlacedResourceIndex(id.Value);
                     if (placedIndex >= 0)
                     {
                         var placed = aliasingManager.GetPlacedResource(placedIndex);
 
-                        // If this placed resource has multiple aliased resources,
+                        // If this placed heap has multiple aliased resources,
                         // we need an aliasing barrier when switching between them
                         if (placed != null && placed.aliasedLogicalResources.Count > 1)
                         {
-                            // Find the resource that used this placed memory most recently before this pass
+                            // Find the heap that used this placed memory most recently before this pass
                             Identifier<RGResource> resourceBefore = default;
                             var mostRecentLastUse = -1;
 
@@ -169,10 +169,10 @@ internal static class RenderGraphBarriers
                             {
                                 if (otherLogicalIndex != id.Value)
                                 {
-                                    // Get resource by global index
+                                    // Get heap by global index
                                     var otherResource = resources.GetResourceByIndex(otherLogicalIndex);
 
-                                    // Check if this resource finished before our resource starts
+                                    // Check if this heap finished before our heap starts
                                     if (otherResource.lastUsePass < pass.index &&
                                         otherResource.lastUsePass > mostRecentLastUse)
                                     {
@@ -182,7 +182,7 @@ internal static class RenderGraphBarriers
                                 }
                             }
 
-                            // If we found a previous resource, insert aliasing barrier
+                            // If we found a previous heap, insert aliasing barrier
                             if (mostRecentLastUse >= 0)
                             {
                                 // Aliasing Requirement: Transition to Undefined, Sync with Predecessor
@@ -215,7 +215,7 @@ internal static class RenderGraphBarriers
         List<CompiledBarrier> compiledBarriers,
         RenderGraphResourceRegistry resources)
     {
-        // Helper to add a compiled barrier for a resource transition
+        // Helper to add a compiled barrier for a heap transition
         void AddTransition(Identifier<RGResource> id, ResourceBarrierData targetState)
         {
             var resource = resources.GetResource(id);

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphBuilder.cs

@@ -22,7 +22,7 @@ public enum ResourceExtractionFlags : byte
 {
     None = 0,
     /// <summary>
-    /// Releases the old resource after extraction.
+    /// Releases the old heap after extraction.
     /// </summary>
     ReleaseAfterExtract = 1 << 0,
 }
@@ -36,19 +36,19 @@ public interface IRenderGraphBuilder : IDisposable
     void AllowPassCulling(bool value);
 
     /// <summary>
-    /// Creates a new texture resource based on the specified desc.
+    /// Creates a new texture heap based on the specified desc.
     /// </summary>
     /// <param name="desc">A structure that defines the properties and configuration of the texture to create.</param>
-    /// <param name="name">The name of the texture resource.</param>
+    /// <param name="name">The name of the texture heap.</param>
-    /// <returns>An identifier for the newly created texture resource.</returns>
+    /// <returns>An identifier for the newly created texture heap.</returns>
     Identifier<RGTexture> CreateTexture(in RGTextureDesc desc, string name);
 
     /// <summary>
-    /// Creates a new buffer resource based on the specified desc.
+    /// Creates a new buffer heap based on the specified desc.
     /// </summary>
     /// <param name="desc">A structure that defines the properties and configuration of the buffer to create.</param>
-    /// <param name="name">The name of the buffer resource.</param>
+    /// <param name="name">The name of the buffer heap.</param>
-    /// <returns>An identifier for the newly created buffer resource.</returns>
+    /// <returns>An identifier for the newly created buffer heap.</returns>
     Identifier<RGBuffer> CreateBuffer(in BufferDesc desc, string name);
 
     /// <summary>
@@ -69,17 +69,17 @@ public interface IRenderGraphBuilder : IDisposable
     Identifier<RGBuffer> UseBuffer(Identifier<RGBuffer> buffer, AccessFlags accessMode);
 
     /// <summary>
-    /// Extracts the actual texture resource associated with the given identifier for use in outside of the render graph execution context.
+    /// Extracts the actual texture heap associated with the given identifier for use in outside of the render graph execution context.
     /// </summary>
     /// <param name="src">The identifier of the texture to be extracted.</param>
-    /// <param name="dst">A handle to receive the actual GPU texture resource.</param>
+    /// <param name="dst">A handle to receive the actual GPU texture heap.</param>
     void QueryTextureExtraction(Identifier<RGTexture> src, Handle<GPUTexture> dst, ResourceExtractionFlags flags = ResourceExtractionFlags.ReleaseAfterExtract);
 
     /// <summary>
-    /// Extracts the actual buffer resource associated with the given identifier for use in outside of the render graph execution context.
+    /// Extracts the actual buffer heap associated with the given identifier for use in outside of the render graph execution context.
     /// </summary>
     /// <param name="src">The identifier of the buffer to be extracted.</param>
-    /// <param name="dst">A handle to receive the actual GPU buffer resource.</param>
+    /// <param name="dst">A handle to receive the actual GPU buffer heap.</param>
     void QueryBufferExtraction(Identifier<RGBuffer> src, Handle<GPUBuffer> dst, ResourceExtractionFlags flags = ResourceExtractionFlags.ReleaseAfterExtract);
 }
 
@@ -94,7 +94,7 @@ public interface IRasterRenderGraphBuilder : IRenderGraphBuilder
     /// <summary>
     /// Specifies that the given buffer will be used for random access operations with the specified access mode within the current context.
     /// </summary>
-    /// <param name="buffer">An identifier for the buffer to be used for random access. Must reference a valid buffer resource.</param>
+    /// <param name="buffer">An identifier for the buffer to be used for random access. Must reference a valid buffer heap.</param>
     /// <returns>An identifier for the buffer.</returns>
     Identifier<RGBuffer> UseRandomAccessBuffer(Identifier<RGBuffer> buffer);
 
@@ -150,7 +150,7 @@ public interface IUnsafeRenderGraphBuilder : IRenderGraphBuilder
     /// <summary>
     /// Specifies that the given buffer will be used for random access operations with the specified access mode within the current context.
     /// </summary>
-    /// <param name="buffer">An identifier for the buffer to be used for random access. Must reference a valid buffer resource.</param>
+    /// <param name="buffer">An identifier for the buffer to be used for random access. Must reference a valid buffer heap.</param>
     /// <returns>An identifier for the buffer.</returns>
     Identifier<RGBuffer> UseRandomAccessBuffer(Identifier<RGBuffer> buffer);
 

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphCompilationCache.cs

@@ -16,16 +16,16 @@ internal sealed class CachedCompilation
     // Culling decisions for each pass
     public readonly List<bool> passCulledFlags = new(64);
 
-    // Physical resource aliasing mappings (logical index -> physical index)
+    // Physical heap aliasing mappings (logical index -> physical index)
     public readonly Dictionary<int, int> logicalToPhysical = new(128);
 
-    // Placed resource metadata
+    // Placed heap metadata
     public readonly List<PlacedResourceData> placedResources = new(32);
 
     // Compiled barriers (stores only target states, queries before state from ResourceManager)
     public readonly List<CompiledBarrier> compiledBarriers = new(128);
 
-    // Real gpu resource
+    // Real gpu heap
     public readonly List<Handle<GPUResource>> backingResources = new(32);
 
     // View state used for this compilation
@@ -44,7 +44,7 @@ internal sealed class CachedCompilation
 }
 
 /// <summary>
-/// Placed resource data for caching.
+/// Placed heap data for caching.
 /// </summary>
 internal struct PlacedResourceData
 {

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphCompiler.cs

@@ -4,7 +4,7 @@ using Ghost.Graphics.RHI;
 namespace Ghost.Graphics.RenderGraphModule;
 
 /// <summary>
-/// Handles compilation of the render graph including pass culling, resource allocation,
+/// Handles compilation of the render graph including pass culling, heap allocation,
 /// barrier compilation, and cache management.
 /// </summary>
 internal sealed class RenderGraphCompiler
@@ -229,7 +229,7 @@ internal sealed class RenderGraphCompiler
         {
             Size = _aliasingManager.Heap.size + 64 * 1024, // Add 64KB padding to avoid potential overflows
             Alignment = ResourceHeap.DEFAULT_ALIGNMENT,
-            HeapFlags = HeapFlags.AlowBufferAndTexture,
+            HeapFlags = HeapFlags.AllowAllBufferAndTexture,
             HeapType = HeapType.Default
         };
 

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphContext.cs

@@ -12,10 +12,10 @@ public interface IRenderGraphContext
 
     Handle<GPUResource> GetActualResource(Identifier<RGResource> resource);
     Handle<GPUTexture> GetActualTexture(Identifier<RGTexture> texture);
-    Handle<RHI.GPUBuffer> GetActualBuffer(Identifier<RGBuffer> buffer);
+    Handle<GPUBuffer> GetActualBuffer(Identifier<RGBuffer> buffer);
 
     Handle<GPUTexture> GetHistoryTexture(ReadOnlySpan<Identifier<RGTexture>> texture, int historyOffset);
-    Handle<RHI.GPUBuffer> GetHistoryBuffer(ReadOnlySpan<Identifier<RGBuffer>> buffer, int historyOffset);
+    Handle<GPUBuffer> GetHistoryBuffer(ReadOnlySpan<Identifier<RGBuffer>> buffer, int historyOffset);
 
     ICommandBuffer GetCommandBufferUnsafe();
 }
@@ -60,8 +60,8 @@ internal sealed class RenderGraphContext : IUnsafeRenderContext
     private TextureFormat _dsvFormat;
     private int _rtvCount;
 
-    private Handle<RHI.GPUBuffer> _activePerMaterialData;
+    private Handle<GPUBuffer> _activePerMaterialData;
-    private Handle<RHI.GPUBuffer> _activePerMeshData;
+    private Handle<GPUBuffer> _activePerMeshData;
     private int _activeMeshIndexCount;
 
     private uint _activeFrameBuffer;
@@ -120,9 +120,9 @@ internal sealed class RenderGraphContext : IUnsafeRenderContext
         return _resources.GetResource(texture.AsResource()).backingResource.AsTexture();
     }
 
-    public Handle<RHI.GPUBuffer> GetActualBuffer(Identifier<RGBuffer> buffer)
+    public Handle<GPUBuffer> GetActualBuffer(Identifier<RGBuffer> buffer)
     {
-        return _resources.GetResource(buffer.AsResource()).backingResource.AsGraphicsBuffer();
+        return _resources.GetResource(buffer.AsResource()).backingResource.AsBuffer();
     }
 
     public Handle<GPUTexture> GetHistoryTexture(ReadOnlySpan<Identifier<RGTexture>> textures, int historyOffset)
@@ -141,11 +141,11 @@ internal sealed class RenderGraphContext : IUnsafeRenderContext
         return GetActualTexture(textures[index]);
     }
 
-    public Handle<RHI.GPUBuffer> GetHistoryBuffer(ReadOnlySpan<Identifier<RGBuffer>> buffers, int historyOffset)
+    public Handle<GPUBuffer> GetHistoryBuffer(ReadOnlySpan<Identifier<RGBuffer>> buffers, int historyOffset)
     {
         if (historyOffset < 0 || historyOffset >= buffers.Length)
         {
-            return Handle<RHI.GPUBuffer>.Invalid;
+            return Handle<GPUBuffer>.Invalid;
         }
 
         var index = (int)(_frameIndex % buffers.Length) - historyOffset;
@@ -172,7 +172,7 @@ internal sealed class RenderGraphContext : IUnsafeRenderContext
         var r = _resourceManager.GetMaterialReference(material);
         if (r.IsFailure)
         {
-            _activePerMaterialData = Handle<RHI.GPUBuffer>.Invalid;
+            _activePerMaterialData = Handle<GPUBuffer>.Invalid;
             return;
         }
 
@@ -185,7 +185,7 @@ internal sealed class RenderGraphContext : IUnsafeRenderContext
         var shaderResult = _resourceManager.GetShaderReference(material.Shader);
         if (shaderResult.IsFailure)
         {
-            _activePerMaterialData = Handle<RHI.GPUBuffer>.Invalid;
+            _activePerMaterialData = Handle<GPUBuffer>.Invalid;
             return;
         }
 
@@ -230,7 +230,7 @@ internal sealed class RenderGraphContext : IUnsafeRenderContext
         var r = _resourceManager.GetMeshReference(mesh);
         if (r.IsFailure)
         {
-            _activePerMeshData = Handle<RHI.GPUBuffer>.Invalid;
+            _activePerMeshData = Handle<GPUBuffer>.Invalid;
             _activeMeshIndexCount = 0;
             return;
         }

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphHasher.cs

@@ -78,7 +78,7 @@ internal static class RenderGraphHasher
     }
 
     /// <summary>
-    /// Computes a hash of a texture resource's structural properties.
+    /// Computes a hash of a texture heap's structural properties.
     /// For imported textures, hashes the backing handle.
     /// For transient textures, hashes the descriptor (respecting size mode).
     /// </summary>
@@ -94,7 +94,7 @@ internal static class RenderGraphHasher
         // Hash imported flag
         writer.Write(resource.isImported);
 
-        // For imported textures, hash the backing resource handle
+        // For imported textures, hash the backing heap handle
         if (resource.isImported)
         {
             writer.Write(resource.backingResource.GetHashCode());

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphNativePassBuilder.cs

@@ -204,7 +204,7 @@ internal sealed class RenderGraphNativePassBuilder
     {
         var laterPass = compiledPasses[passB];
 
-        // Build a set of render target resource IDs (color + depth)
+        // Build a set of render target heap IDs (color + depth)
         var renderTargets = new HashSet<Identifier<RGResource>>();
         for (var i = 0; i <= laterPass.maxColorIndex; i++)
         {
@@ -241,7 +241,7 @@ internal sealed class RenderGraphNativePassBuilder
 
     /// <summary>
     /// Infers optimal load/store operations for all attachments in a native render pass.
-    /// Uses resource lifetime information to minimize memory bandwidth (critical for TBDR GPUs).
+    /// Uses heap lifetime information to minimize memory bandwidth (critical for TBDR GPUs).
     /// </summary>
     private void InferLoadStoreOps(NativeRenderPass nativePass)
     {

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphResourcePool.cs

@@ -211,7 +211,7 @@ internal sealed class RenderGraphResourceRegistry
         return new Identifier<RGTexture>(resource.index);
     }
 
-    public Identifier<RGBuffer> ImportBuffer(ref readonly BufferDesc desc, Handle<RHI.GPUBuffer> buffer, string name)
+    public Identifier<RGBuffer> ImportBuffer(ref readonly BufferDesc desc, Handle<GPUBuffer> buffer, string name)
     {
         var resource = _pool.Rent<RenderGraphResource>();
         resource.name = name;
@@ -256,7 +256,7 @@ internal sealed class RenderGraphResourceRegistry
     }
 
     /// <summary>
-    /// Gets resource by global index. Use this when iterating over all resources.
+    /// Gets heap by global index. Use this when iterating over all resources.
     /// </summary>
     public RenderGraphResource GetResourceByIndex(int index)
     {

src/Runtime/Ghost.Graphics/RenderSystem.cs

@@ -163,7 +163,7 @@ public class RenderSystem : IDisposable
                 throw new NotSupportedException($"The specified graphics API '{desc.GraphicsAPI}' is not supported.");
         }
 
-        _resourceManager = new ResourceManager(_graphicsEngine.ResourceAllocator, _graphicsEngine.ResourceDatabase);
+        _resourceManager = new ResourceManager(_graphicsEngine.Device, _graphicsEngine.ResourceAllocator, _graphicsEngine.ResourceDatabase);
         _swapChainManager = new SwapChainManager(_graphicsEngine);
 
         // Create frame resources for synchronization
@@ -246,7 +246,7 @@ public class RenderSystem : IDisposable
                 var flushFence = _graphicsEngine.Device.GraphicsQueue.Signal(_gpuFenceValue);
                 _graphicsEngine.Device.GraphicsQueue.WaitForValue(flushFence);
 
-                // Sync the current frame resource to this new fence to keep state consistent
+                // Sync the current frame heap to this new fence to keep state consistent
                 frameResource.FenceValue = flushFence;
 
                 foreach (var resource in _frameResources)
@@ -322,7 +322,7 @@ public class RenderSystem : IDisposable
             }
 
             // End the frame and present
-            _resourceManager.EndFrame(_cpuFenceValue);
+            _resourceManager.EndFrame(_gpuFenceValue);
             r = _graphicsEngine.EndFrame(_gpuFenceValue);
 
             if (r.IsFailure)
@@ -426,9 +426,11 @@ public class RenderSystem : IDisposable
 
         _renderPipeline.Dispose();
 
-        _swapChainManager.Dispose();
         _resourceManager.Dispose();
         _graphicsEngine.Dispose();
+
+        _swapChainManager.Dispose();
+
         _shutdownEvent.Dispose();
 
         _disposed = true;

src/Runtime/Ghost.Graphics/ResourceManager.Pool.cs

@@ -0,0 +1,271 @@
+using Ghost.Core;
+using Ghost.Graphics.RHI;
+using Misaki.HighPerformance.LowLevel.Buffer;
+using Misaki.HighPerformance.LowLevel.Collections;
+using System.Diagnostics;
+
+namespace Ghost.Graphics;
+
+public partial class ResourceManager
+{
+    private const ulong _DEFAULT_TRANSIENT_PAGE_SIZE = 16 * 1024 * 1024; // 16MB
+
+    private struct Page
+    {
+        public Handle<GPUResource> heap;
+        public ulong offset;
+
+        public HeapFlags heapFlags;
+        public HeapType heapType;
+    }
+
+    private struct RetiringPage
+    {
+        public Page page;
+        public ulong retireFrame;
+    }
+
+    private UnsafeList<Page> _activePages;
+    private UnsafeQueue<RetiringPage> _retiringPages;
+
+    private UnsafeList<Handle<GPUResource>> _oversizedTransientResources;
+
+    private void InitializePool()
+    {
+        _activePages = new UnsafeList<Page>(4, Allocator.Persistent);
+        _retiringPages = new UnsafeQueue<RetiringPage>(4, Allocator.Persistent);
+        _oversizedTransientResources = new UnsafeList<Handle<GPUResource>>(4, Allocator.Persistent);
+    }
+
+    private Error CreateNewActivePage(HeapType heapType, HeapFlags heapFlags)
+    {
+        var allocationDesc = new AllocationDesc
+        {
+            Size = _DEFAULT_TRANSIENT_PAGE_SIZE,
+            Alignment = 65536, // 64KB
+            HeapType = heapType,
+            HeapFlags = heapFlags,
+        };
+
+        var buffer = _resourceAllocator.Allocate(in allocationDesc, $"Page {_activePages.Count + _retiringPages.Count}");
+        if (buffer.IsInvalid)
+        {
+            return Error.OutOfMemory;
+        }
+
+        _activePages.Add(new Page
+        {
+            heap = buffer,
+            offset = 0,
+            heapFlags = heapFlags,
+            heapType = heapType,
+        });
+
+        return Error.None;
+    }
+
+    public Handle<GPUTexture> CreateTransientTexture(ref readonly TextureDesc desc, string? name = null)
+    {
+        var isRTOrDS = desc.Usage.HasFlag(TextureUsage.DepthStencil) || desc.Usage.HasFlag(TextureUsage.RenderTarget);
+        var size = _resourceAllocator.GetSizeInfo(ResourceDesc.Texture(desc));
+
+        if (size.Size > _DEFAULT_TRANSIENT_PAGE_SIZE)
+        {
+            var texHandle = _resourceAllocator.CreateTexture(in desc, name);
+            if (texHandle.IsValid)
+            {
+                _oversizedTransientResources.Add(texHandle.AsResource());
+            }
+
+            return texHandle;
+        }
+
+        var requiredHeapFlags = _renderDevice.FeatureSupport.HasFlag(FeatureSupport.AliasBuffersAndTextures) ?
+            HeapFlags.AllowAllBufferAndTexture :
+            isRTOrDS ? HeapFlags.AllowOnlyRTAndDS : HeapFlags.AllowOnlyTextures;
+
+        var foundPageIndex = -1;
+        var alignedOffset = 0UL;
+
+        for (var i = 0; i < _activePages.Count; i++)
+        {
+            ref var p = ref _activePages[i];
+
+            if (p.heapType != HeapType.Default)
+            {
+                continue;
+            }
+
+            if (p.heapFlags != requiredHeapFlags && p.heapFlags != HeapFlags.AllowAllBufferAndTexture)
+            {
+                continue;
+            }
+
+            var proposedOffset = (p.offset + (size.Alignment - 1)) & ~(size.Alignment - 1);
+
+            if (proposedOffset + size.Size <= _DEFAULT_TRANSIENT_PAGE_SIZE)
+            {
+                foundPageIndex = i;
+                alignedOffset = proposedOffset;
+                break;
+            }
+        }
+
+        if (foundPageIndex == -1)
+        {
+            var error = CreateNewActivePage(HeapType.Default, requiredHeapFlags);
+            if (error != Error.None)
+            {
+                Debug.Fail($"Failed to create a new page for transient texture: {error}");
+                return Handle<GPUTexture>.Invalid;
+            }
+
+            foundPageIndex = _activePages.Count - 1;
+            alignedOffset = 0;
+        }
+
+        ref var page = ref _activePages[foundPageIndex];
+
+        var handle = _resourceAllocator.CreateTexture(in desc, name, new CreationOptions
+        {
+            AllocationType = ResourceAllocationType.Suballocation,
+            Heap = page.heap,
+            Offset = alignedOffset,
+        });
+
+        page.offset = alignedOffset + size.Size;
+
+        return handle;
+    }
+
+    public Handle<GPUBuffer> CreateTransientBuffer(ref readonly BufferDesc desc, string? name = null)
+    {
+        var size = _resourceAllocator.GetSizeInfo(ResourceDesc.Buffer(desc));
+        if (size.Size > _DEFAULT_TRANSIENT_PAGE_SIZE)
+        {
+            var bufHandle = _resourceAllocator.CreateBuffer(in desc, name);
+            if (bufHandle.IsValid)
+            {
+                _oversizedTransientResources.Add(bufHandle.AsResource());
+            }
+
+            return bufHandle;
+        }
+
+        var requiredHeapType = desc.MemoryType switch
+        {
+            ResourceMemoryType.Upload => HeapType.Upload,
+            ResourceMemoryType.Readback => HeapType.Readback,
+            _ => HeapType.Default
+        };
+
+        var requiredHeapFlags = _renderDevice.FeatureSupport.HasFlag(FeatureSupport.AliasBuffersAndTextures) ?
+            HeapFlags.AllowAllBufferAndTexture : HeapFlags.AllowOnlyBuffers;
+
+        var foundPageIndex = -1;
+        var alignedOffset = 0UL;
+
+        for (var i = 0; i < _activePages.Count; i++)
+        {
+            ref var p = ref _activePages[i];
+
+            if (p.heapType != requiredHeapType)
+            {
+                continue;
+            }
+
+            if (p.heapFlags != requiredHeapFlags && p.heapFlags != HeapFlags.AllowAllBufferAndTexture)
+            {
+                continue;
+            }
+
+            var proposedOffset = (p.offset + (size.Alignment - 1)) & ~(size.Alignment - 1);
+
+            if (proposedOffset + size.Size <= _DEFAULT_TRANSIENT_PAGE_SIZE)
+            {
+                foundPageIndex = i;
+                alignedOffset = proposedOffset;
+                break;
+            }
+        }
+
+        if (foundPageIndex == -1)
+        {
+            var error = CreateNewActivePage(requiredHeapType, requiredHeapFlags);
+            if (error != Error.None)
+            {
+                Debug.Fail($"Failed to create a new page for transient buffer: {error}");
+                return Handle<GPUBuffer>.Invalid;
+            }
+
+            foundPageIndex = _activePages.Count - 1;
+            alignedOffset = 0;
+        }
+
+        ref var page = ref _activePages[foundPageIndex];
+
+        var handle = _resourceAllocator.CreateBuffer(in desc, name, new CreationOptions
+        {
+            AllocationType = ResourceAllocationType.Suballocation,
+            Heap = page.heap,
+            Offset = alignedOffset,
+        });
+
+        page.offset = alignedOffset + size.Size;
+
+        return handle;
+    }
+
+    private void EndFramePool(ulong gpuFrame)
+    {
+        for (var i = 0; i < _activePages.Count; i++)
+        {
+            ref var page = ref _activePages[i];
+            _retiringPages.Enqueue(new RetiringPage
+            {
+                page = page,
+                retireFrame = _cpuFrame
+            });
+        }
+
+        _activePages.Clear();
+
+        while (_retiringPages.TryPeek(out var retiringPage) && retiringPage.retireFrame <= gpuFrame)
+        {
+            _retiringPages.Dequeue();
+
+            // Reset the page for reuse
+            retiringPage.page.offset = 0;
+            _activePages.Add(retiringPage.page);
+        }
+
+        for (var i = 0; i < _oversizedTransientResources.Count; i++)
+        {
+            _resourceDatabase.ReleaseResource(_oversizedTransientResources[i]);
+        }
+
+        _oversizedTransientResources.Clear();
+    }
+
+    private void DisposePool()
+    {
+        foreach (var page in _activePages)
+        {
+            _resourceDatabase.ReleaseResourceImmediately(page.heap);
+        }
+
+        foreach (var page in _retiringPages)
+        {
+            _resourceDatabase.ReleaseResourceImmediately(page.page.heap);
+        }
+
+        foreach (var resource in _oversizedTransientResources)
+        {
+            _resourceDatabase.ReleaseResourceImmediately(resource);
+        }
+
+        _activePages.Dispose();
+        _retiringPages.Dispose();
+        _oversizedTransientResources.Dispose();
+    }
+}

src/Runtime/Ghost.Graphics/ResourceManager.cs

@@ -8,7 +8,7 @@ using System.Diagnostics;
 
 namespace Ghost.Graphics;
 
-public sealed class ResourceManager : IDisposable
+public sealed partial class ResourceManager : IDisposable
 {
     private readonly struct ResourceReturnEntry
     {
@@ -22,6 +22,7 @@ public sealed class ResourceManager : IDisposable
         }
     }
 
+    private readonly IRenderDevice _renderDevice;
     private readonly IResourceAllocator _resourceAllocator;
     private readonly IResourceDatabase _resourceDatabase;
 
@@ -31,15 +32,13 @@ public sealed class ResourceManager : IDisposable
 
     private readonly MaterialPaletteStore _materialPalettes;
 
-    private ulong _currentFrame;
+    private ulong _cpuFrame;
-
-    private UnsafeHashMap<ResourceDesc, UnsafeQueue<Handle<GPUResource>>> _resourceCache;
-    private UnsafeQueue<ResourceReturnEntry> _resourceReturnQueue;
 
     private bool _disposed;
 
-    public ResourceManager(IResourceAllocator resourceAllocator, IResourceDatabase resourceDatabase)
+    public ResourceManager(IRenderDevice renderDevice, IResourceAllocator resourceAllocator, IResourceDatabase resourceDatabase)
     {
+        _renderDevice = renderDevice;
         _resourceAllocator = resourceAllocator;
         _resourceDatabase = resourceDatabase;
 
@@ -49,8 +48,7 @@ public sealed class ResourceManager : IDisposable
 
         _materialPalettes = new MaterialPaletteStore();
     
-        _resourceCache = new UnsafeHashMap<ResourceDesc, UnsafeQueue<Handle<GPUResource>>>(32, Allocator.Persistent);
+        InitializePool();
-        _resourceReturnQueue = new UnsafeQueue<ResourceReturnEntry>(32, Allocator.Persistent);
     }
 
     ~ResourceManager()
@@ -58,30 +56,16 @@ public sealed class ResourceManager : IDisposable
         Dispose();
     }
 
-    internal void BeginFrame(ulong currentFrame)
+    internal void BeginFrame(ulong cpuFrame)
     {
         Debug.Assert(!_disposed);
-        _currentFrame = currentFrame;
+        _cpuFrame = cpuFrame;
     }
 
-    internal void EndFrame(ulong completedFrame)
+    internal void EndFrame(ulong gpuFrame)
     {
         Debug.Assert(!_disposed);
-
+        EndFramePool(gpuFrame);
-        while (_resourceReturnQueue.TryPeek(out var entry) && entry.returnFrame <= completedFrame)
-        {
-            _resourceReturnQueue.Dequeue();
-            var result = _resourceDatabase.GetResourceDescription(entry.handle);
-            Debug.Assert(result.IsSuccess);
-
-            ref var queue = ref _resourceCache.GetValueRefOrAddDefault(result.Value, out var exist);
-            if (!exist)
-            {
-                queue = new UnsafeQueue<Handle<GPUResource>>(4, Allocator.Persistent);
-            }
-
-            queue.Enqueue(entry.handle);
-        }
     }
 
     /// <summary>
@@ -198,7 +182,7 @@ public sealed class ResourceManager : IDisposable
     }
 
     /// <summary>
-    /// Releases the mesh resource associated with the specified handle, freeing any resources held by it. Includes both CPU and GPU resources.
+    /// Releases the mesh heap associated with the specified handle, freeing any resources held by it. Includes both CPU and GPU resources.
     /// </summary>
     /// <param name="handle">The handle of the mesh to release. Must refer to a mesh that was previously created and not already released.</param>
     public void ReleaseMesh(Handle<Mesh> handle)
@@ -364,38 +348,6 @@ public sealed class ResourceManager : IDisposable
         shader.ReleaseResource(_resourceDatabase);
     }
 
-    public Handle<GPUResource> GetPooledResource(in ResourceDesc desc)
-    {
-        Debug.Assert(!_disposed);
-
-        ref var queue = ref _resourceCache.GetValueRef(desc, out var exist);
-        if (exist && queue.TryDequeue(out Handle<GPUResource> handle))
-        {
-            return handle;
-        }
-
-        handle = desc.Type switch
-        {
-            ResourceType.Buffer => _resourceAllocator.CreateBuffer(in desc.BufferDescription, "PooledBuffer").AsResource(),
-            ResourceType.Texture => _resourceAllocator.CreateTexture(in desc.TextureDescription, "PooledTexture").AsResource(),
-            _ => throw new ArgumentException("Invalid resource type.", nameof(desc)),
-        };
-
-        return handle;
-    }
-
-    public void ReturnPooledResource(Handle<GPUResource> handle)
-    {
-        Debug.Assert(!_disposed);
-
-        if (handle.IsInvalid)
-        {
-            return;
-        }
-
-        _resourceReturnQueue.Enqueue(new ResourceReturnEntry(handle, _currentFrame));
-    }
-
     public void Dispose()
     {
         if (_disposed)
@@ -423,19 +375,7 @@ public sealed class ResourceManager : IDisposable
         _shaders.Dispose();
         _materialPalettes.Dispose();
 
-        foreach (var kvp in _resourceCache)
+        DisposePool();
-        {
-            var queue = kvp.Value;
-            while (queue.TryDequeue(out var handle))
-            {
-                _resourceDatabase.ReleaseResource(handle);
-            }
-
-            queue.Dispose();
-        }
-
-        _resourceCache.Dispose();
-        _resourceReturnQueue.Dispose();
 
         _disposed = true;
         GC.SuppressFinalize(this);

src/Runtime/Ghost.Graphics/Shaders/Includes/S2H/s2h_3d.hlsl

@@ -0,0 +1,354 @@
+//////////////////////////////////////////////////////////////////////////
+//   Shader To Human (S2H) - HLSL/GLSL library for debugging shaders    //
+//  Copyright (c) 2024-2025 Electronic Arts Inc.  All rights reserved.  //
+//////////////////////////////////////////////////////////////////////////
+
+// Example:
+// #include "s2h.h"
+// #include "s2h_3d.h"
+// {
+//   struct Context3D context;
+//   // todo
+//   s2h_init(context);
+// }
+
+#ifndef S2H_3D_INCLUDE
+#define S2H_3D_INCLUDE
+
+struct Context3D
+{ 
+    // ray origin
+    float3 ro;
+    // ray direction, normalized?
+    float3 rd;
+    // surfacePos = ro + rd * depth
+    float depth;
+    //
+    float4 dstColor;
+};
+//
+void s2h_init(out Context3D context, float3 ro, float3 rd);
+// @param thickness e.g. 0.09f
+void s2h_drawLineWS(inout Context3D context, float3 from, float3 to, float4 color, float thickness);
+// AABB: Axis Aligned Bounding Box
+void s2h_drawAABB(inout Context3D context, float3 center, float3 halfSize, float4 color);
+//
+void s2h_drawArrowWS(inout Context3D context, float3 from, float3 to, float4 color, float thickness);
+// @param worldFromObject aka objectToWorld
+// @param r in world space units
+void s2h_drawBasis(inout Context3D context, float4x4 worldFromObject, float r);
+// @param radius e.g. 0.1f
+void s2h_drawSphereWS(inout Context3D context, float3 pos, float4 color, float radius);
+// 8x8 checker board with X (red) and Z (blue) around offset pointing up (Y+)
+void s2h_drawCheckerBoard(inout Context3D context, float3 offset);
+// infinitely far, +/- X/Z and horizon, useful to having some background for the user to orient themselves
+void s2h_drawSkybox(inout Context3D context);
+
+// implementation ----------------------------------------------------------------------
+
+// @param ro ray origin
+// @param ro ray direction
+void s2h_init(out Context3D context, float3 ro, float3 rd)
+{
+    context.ro = ro;
+    context.rd = rd;
+    context.depth = S2H_FLT_MAX;
+    context.dstColor = float4(0, 0, 0, 0);
+}
+
+// Inigo Quilez sphere ray intersection https://iquilezles.org/articles/intersectors
+// sphere of size ra centered at point ce
+float2 s2h_sphIntersect( in float3 ro, in float3 rd, in float3 ce, float ra )
+{
+    float3 oc = ro - ce;
+    float b = dot( oc, rd );
+    float c = dot( oc, oc ) - ra*ra;
+    float h = b*b - c;
+    if( h<0.0 ) return float2(-1.0, -1.0); // no intersection
+    h = sqrt( h );
+    return float2( -b-h, -b+h );
+}
+// Inigo Quilez box ray intersection https://iquilezles.org/articles/intersectors
+// axis aligned box centered at the origin, with size boxSize
+float2 s2h_boxIntersection( in float3 ro, in float3 rd, float3 boxSize, out float3 outNormal ) 
+{
+    float3 m = 1.0/rd; // can precompute if traversing a set of aligned boxes
+    float3 n = m*ro;   // can precompute if traversing a set of aligned boxes
+    float3 k = abs(m)*boxSize;
+    float3 t1 = -n - k;
+    float3 t2 = -n + k;
+    float tN = max( max( t1.x, t1.y ), t1.z );
+    float tF = min( min( t2.x, t2.y ), t2.z );
+    if( tN>tF || tF<0.0) return float2(-1.0, -1.0); // no intersection
+    outNormal = (tN>0.0) ? step(float3(tN, tN, tN),t1) : // ro outside the box
+                        step(t2,float3(tF, tF, tF));  // ro inside the box
+    outNormal *= -sign(rd);
+    return float2( tN, tF );
+}
+// Inigo Quilez box cylinder intersection https://iquilezles.org/articles/intersectors
+// cylinder defined by extremes a and b, and radious ra
+float4 s2h_cylIntersect( in float3 ro, in float3 rd, in float3 a, in float3 b, float ra )
+{
+    float3  ba = b  - a;
+    float3  oc = ro - a;
+    float baba = dot(ba,ba);
+    float bard = dot(ba,rd);
+    float baoc = dot(ba,oc);
+    float k2 = baba            - bard*bard;
+    float k1 = baba*dot(oc,rd) - baoc*bard;
+    float k0 = baba*dot(oc,oc) - baoc*baoc - ra*ra*baba;
+    float h = k1*k1 - k2*k0;
+    if( h<0.0 ) return float4(-1.0, -1.0, -1.0, -1.0);//no intersection
+    h = sqrt(h);
+    float t = (-k1-h)/k2;
+    // body
+    float y = baoc + t*bard;
+    if( y>0.0 && y<baba ) return float4( t, (oc+t*rd - ba*y/baba)/ra );
+    // caps
+    t = ( ((y<0.0) ? 0.0 : baba) - baoc)/bard;
+    if( abs(k1+k2*t)<h )
+    {
+        return float4( t, ba*sign(y)/sqrt(baba) );
+    }
+    return float4(-1.0, -1.0, -1.0, -1.0);//no intersection
+}
+// normal at point p of cylinder (a,b,ra), see above
+float3 s2h_cylNormal( in float3 p, in float3 a, in float3 b, float ra )
+{
+    float3  pa = p - a;
+    float3  ba = b - a;
+    float baba = dot(ba,ba);
+    float paba = dot(pa,ba);
+    float h = dot(pa,ba)/baba;
+    return (pa - ba*h)/ra;
+}
+float s2h_dot2(float3 p)
+{
+    return dot(p,p);
+}
+// cone defined by extremes pa and pb, and radious ra and rb
+// Only one square root and one division is emplyed in the worst case. s2h_dot2(v) is dot(v,v)
+// @param float4(t, normal)
+float4 s2h_coneIntersect( in float3 ro, in float3 rd, in float3 pa, in float3 pb, in float ra, in float rb )
+{
+    float3  ba = pb - pa;
+    float3  oa = ro - pa;
+    float3  ob = ro - pb;
+    float m0 = dot(ba,ba);
+    float m1 = dot(oa,ba);
+    float m2 = dot(rd,ba);
+    float m3 = dot(rd,oa);
+    float m5 = dot(oa,oa);
+    float m9 = dot(ob,ba); 
+            
+    // caps
+    if( m1<0.0 )
+    {
+        if( s2h_dot2(oa*m2-rd*m1)<(ra*ra*m2*m2) ) // delayed division
+            return float4(-m1/m2,-ba*rsqrt(m0));
+    }
+    else if( m9>0.0 )
+    {
+        float t = -m9/m2;                     // NOT delayed division
+        if( s2h_dot2(ob+rd*t)<(rb*rb) )
+            return float4(t,ba*rsqrt(m0));
+    }
+            
+    // body
+    float rr = ra - rb;
+    float hy = m0 + rr*rr;
+    float k2 = m0*m0    - m2*m2*hy;
+    float k1 = m0*m0*m3 - m1*m2*hy + m0*ra*(rr*m2*1.0        );
+    float k0 = m0*m0*m5 - m1*m1*hy + m0*ra*(rr*m1*2.0 - m0*ra);
+    float h = k1*k1 - k2*k0;
+    if( h<0.0 ) return float4(-1.0, -1.0, -1.0, -1.0); //no intersection
+    float t = (-k1-sqrt(h))/k2;
+    float y = m1 + t*m2;
+    if( y<0.0 || y>m0 ) return float4(-1.0, -1.0, -1.0, -1.0); //no intersection
+    return float4(t, normalize(m0*(m0*(oa+t*rd)+rr*ba*ra)-ba*hy*y));
+}
+
+void s2h_drawAABB(inout Context3D context, float3 center, float3 halfSize, float4 color)
+{
+    float3 normal;
+    float2 hit = s2h_boxIntersection(context.ro - center, context.rd, halfSize, normal);
+
+    if(hit.y > 0.0f && hit.x < context.depth)
+    {
+        context.depth = hit.x;
+        context.dstColor = color;
+        context.dstColor = lerp(context.dstColor, float4(normal * 0.5f + 0.5f, 1), 0.3f);
+    }
+}
+
+void s2h_drawLineWS(inout Context3D context, float3 from, float3 to, float4 color, float thickness)
+{
+    float2 hit = s2h_cylIntersect(context.ro, context.rd, from, to, thickness).xy;
+
+    if(hit.x > 0.0 && hit.x < context.depth)
+    {
+        context.depth = hit.x;
+        float3 p = context.ro + context.depth * context.rd;
+        float3 normal = s2h_cylNormal(p, from, to, thickness);
+        // todo: refine shading
+        color.rgb = lerp(color.rgb, normal * 0.5f + 0.5f, 0.3f);
+        context.dstColor = color;
+    }
+}
+
+void s2h_drawArrowWS(inout Context3D context, float3 from, float3 to, float4 color, float thickness)
+{
+    float4 hit = s2h_coneIntersect(context.ro, context.rd, from, to, thickness, 0.0f);
+
+    if(hit.x > 0.0 && hit.x < context.depth)
+    {
+        context.depth = hit.x;
+        float3 normal = hit.yzw;
+        // todo: refine shading
+        color.rgb = lerp(color.rgb, normal * 0.5 + 0.5, 0.3);
+        context.dstColor = color;
+    }
+}
+
+void s2h_drawBasis(inout Context3D context, float4x4 worldFromObject, float r)
+{
+    float4 oHom = mul(worldFromObject, float4(0, 0, 0, 1));
+    float4 xHom = mul(worldFromObject, float4(r, 0, 0, 1));
+    float4 yHom = mul(worldFromObject, float4(0, r, 0, 1));
+    float4 zHom = mul(worldFromObject, float4(0, 0, r, 1));
+
+    float3 o = oHom.xyz / oHom.w;
+    float3 x = xHom.xyz / xHom.w;
+    float3 y = yHom.xyz / yHom.w;
+    float3 z = zHom.xyz / zHom.w;
+
+    s2h_drawArrowWS(context, o, x, float4(1, 0, 0, 1), 0.09f);
+    s2h_drawArrowWS(context, o, y, float4(0, 1, 0, 1), 0.09f);
+    s2h_drawArrowWS(context, o, z, float4(0, 0, 1, 1), 0.09f);
+}
+
+void s2h_drawSphereWS(inout Context3D context, float3 pos, float4 color, float radius)
+{
+    float2 hit = s2h_sphIntersect(context.ro, context.rd, pos, radius);
+
+    if(hit.x > 0.0 && hit.x < context.depth)
+    {
+        float3 hitPos = context.ro + hit.x * context.rd;
+        float3 normal = normalize(hitPos - pos);
+
+        context.depth = hit.x;
+        // todo: refine shading
+        color.rgb = lerp(color.rgb, normal * 0.5 + 0.5, 0.3);
+        context.dstColor = color;
+    }
+}
+
+void s2h_drawCheckerBoard(inout Context3D context, float3 offset)
+{
+    float3 pos = float3(0, -0.2, 0) + offset;
+    float3 size = float3(4.4, 0.2, 4.4);
+    float3 normal;
+    float2 hit = s2h_boxIntersection(context.ro - pos, context.rd, size, normal);
+
+    if(hit.y > 0.0f && hit.x < context.depth)
+    {
+        context.depth = hit.x;
+
+        float3 hitPos = context.ro + hit.x * context.rd;
+        float2 uv = hitPos.zx;
+
+        float value = 1.0f;
+                
+        if(abs(uv.x) < 4.0f && abs(uv.y) < 4.0f)
+            value = frac(floor(uv.x) * 0.5f + floor(uv.y) * 0.5f) > 0.25f ? 0.4f : 0.6f;
+
+        context.dstColor = float4(value, value, value, 1);
+
+        if(abs(uv.x) < (4.0f - uv.y) * 0.1f && uv.y > 0.0f)
+            context.dstColor.rgb = float3(1,0,0);
+        if(abs(uv.y) < (4.0f - uv.x) * 0.1f && uv.x > 0.0f)
+            context.dstColor.rgb = float3(0,0,1);
+        if(dot(uv, uv) < 0.25f)
+            context.dstColor.rgb = float3(0,1,0);
+
+        context.dstColor = lerp(context.dstColor, float4(normal * 0.5f + 0.5f, 1), 0.3f);
+    }
+}
+
+void s2h_drawSkybox(inout Context3D context)
+{
+	if(context.depth == S2H_FLT_MAX)
+	{
+		float3 d = context.rd;
+
+		float pi = 3.14159265f;
+
+		// assuming normalized rd
+		float2 uv = float2(-atan2(d.z, d.x) / pi + 1.0, acos(d.y) / pi);
+
+		float2 px = uv * float2(s2h_fontSize() * 8.0, s2h_fontSize() * 4.0);
+
+		float tileX = s2h_fontSize() * 4.0;
+
+		// 4*4 characters around the x axis
+		ContextGather ui;
+		s2h_init(ui, float2(frac(px.x / tileX + 0.5f) * tileX, px.y));
+
+		// horizon
+		ui.dstColor.rgb = float3(1,1,1) * saturate(1.0f - pow(abs(d.y), 0.2f));
+		ui.dstColor.a = 1.0f;
+
+		// grid
+		{
+			float2 gridXY = frac(ui.pxPos);
+			gridXY = min(gridXY, float2(1.0f, 1.0f) - gridXY);
+			// 0 .. 0.5
+			float grid = min(gridXY.x, gridXY.y);
+			ui.dstColor.rgb = lerp(ui.dstColor.rgb, float3(1,1,1), 0.07f * saturate(1.0f - grid * 30.0f));
+		}
+
+		bool xzAxis = abs(d.x) > abs(d.z);
+
+		bool posAxis = xzAxis ? (d.x > 0.0f) : (d.z > 0.0f);
+
+		s2h_setCursor(ui, float2(0, 12));
+		ui.textColor.rgb = xzAxis ? float3(1, 0, 0) : float3(0, 0, 1);
+		ui.textColor.a = 0.4f;
+		s2h_printTxt(ui, _SPACE);
+		s2h_printTxt(ui, posAxis ? _PLUS : _MINUS);
+		s2h_printTxt(ui, xzAxis ? _X : _Z);
+
+		context.dstColor = ui.dstColor;
+	}
+}
+
+void scene(inout Context3D context);
+
+void sceneWithShadows(inout Context3D context)
+{
+    scene(context);
+
+    float4 litScene = context.dstColor;
+
+    // shadow ray, experiment, todo: expose light direction
+    if(context.depth < S2H_FLT_MAX)
+    {
+        // 0..1
+        float visible;
+        {
+            const float bias = 0.001; 
+            Context3D shadowContext;
+            s2h_init(shadowContext, context.ro + context.depth * context.rd, normalize(float3(1.0,3.0,2.0)));
+            shadowContext.ro += bias * shadowContext.rd;
+
+            scene(shadowContext);
+            visible = shadowContext.depth == S2H_FLT_MAX ? 1.0 : 0.0;
+        }
+
+        // shadows are grey, todo: expose ambient color
+        float shadowFactor = 0.5 - visible * 0.5;
+        context.dstColor.rgb = lerp(litScene.rgb, float3(0.0, 0.0, 0.0), shadowFactor);
+    }
+}
+
+#endif // S2H_3D_INCLUDE

src/Runtime/Ghost.Graphics/Shaders/Includes/S2H/s2h_scatter.hlsl

@@ -0,0 +1,245 @@
+//////////////////////////////////////////////////////////////////////////
+//   Shader To Human (S2H) - HLSL/GLSL library for debugging shaders    //
+//  Copyright (c) 2024-2025 Electronic Arts Inc.  All rights reserved.  //
+//////////////////////////////////////////////////////////////////////////
+
+// Example:
+// #include "s2h.h"
+// #include "s2h_scatter.h"
+// {
+//   struct ContextScatter ui;
+//   s2h_init(ui);
+//   s2h_printTxt(ui, _A, _B);
+// }
+// void onGfxForAllScatter(int2 pxPos, float4 color) 
+// {
+//	 g_computeOutput[pxPos] = color;
+// }
+
+#ifndef S2H_SCATTER_INCLUDE
+#define S2H_SCATTER_INCLUDE
+
+// documentation:
+struct ContextScatter
+{
+	// RGBA, alpha 1 is assumed to be opaque
+	float4 textColor;
+
+	// private, for internal use, might change --------
+
+	// in pixels
+	int2 pxCursor;
+	// window left top, set by s2h_init()
+	int pxLeftX;
+	// 1/2/3/4, call s2h_setScale()
+	int scale;
+};
+
+// first call this
+void s2h_init(out ContextScatter ui);
+// set text cursor position, next printLF() will reset to this x position
+void s2h_setCursor(inout ContextScatter ui, float2 inpxLeftTop);
+// @param scale 1:pixel perfect, 2:2x, 3:3x, ..
+void s2h_setScale(inout ContextScatter ui, uint scale);
+// e.g. ui.s2h_printTxt('I', ' ', 'a', 'm');
+// @param a ascii character or 0
+void s2h_printTxt(inout ContextScatter ui, uint a, uint b, uint c, uint d, uint e, uint f);
+// jump to next line
+void s2h_printLF(inout ContextScatter ui);
+// @param value e.g. 123, 0
+void s2h_printInt(inout ContextScatter ui, int value);
+// print hexadecimal e.g. "0000aa34"
+// @param value 32bit e.g. 0x123, 0xff00
+void s2h_printHex(inout ContextScatter ui, uint value);
+// @param output e.g. g_output from RWTexture2D<float3> g_output : register(u0, space0);
+// @param pos in pixels from left top, left top of the printout
+// @param value
+void s2h_printFloat(inout ContextScatter ui, float value);
+// block in a 8x8 character
+void s2h_printBlock(inout ContextScatter ui, float4 color);
+// circle in a 8x8 character
+void s2h_printDisc(inout ContextScatter ui, float4 color);
+// don't use directly
+void s2h_printCharacter(inout ContextScatter ui, uint ascii);
+// no AA
+void s2h_drawCrosshair(inout ContextScatter ui, float2 pxCenter, float pxRadius, float4 color);
+
+// implementation ----------------------------------------------------------------------
+
+void s2h_init(out ContextScatter ui)
+{ 
+	// white, opaque
+	ui.textColor = float4(1, 1, 1, 1);
+	ui.pxCursor = int2(0, 0);
+	ui.pxLeftX = ui.pxCursor.x;
+	ui.scale = 1;
+} 
+
+void s2h_setCursor(inout ContextScatter ui, float2 inpxLeftTop)
+{
+	ui.pxCursor = inpxLeftTop; 
+	ui.pxLeftX = inpxLeftTop.x;
+}
+
+void s2h_setScale(inout ContextScatter ui, uint scale)
+{
+	ui.scale = scale;
+}
+
+// implement this in your code
+void onGfxForAllScatter(int2 pxPos, float4 color);
+
+void s2h_printCharacter(inout ContextScatter ui, uint ascii)
+{
+	[loop] for(int y = 0; y < 8 * ui.scale; ++y)
+	[loop] for(int x = 0; x < 8 * ui.scale; ++x)
+		if(s2h_fontLookup(ascii, int2(x, y) / ui.scale))
+			onGfxForAllScatter(ui.pxCursor + int2(x, y), ui.textColor);
+
+	ui.pxCursor.x += 8 * ui.scale;
+}
+
+void s2h_drawCrosshair(inout ContextScatter ui, float2 pxCenter, float pxRadius, float4 color)
+{
+	// avoiding int math for better performance
+	onGfxForAllScatter(pxCenter, ui.textColor);
+
+	[loop] for(float i = 1; i < pxRadius; ++i)
+	{
+		onGfxForAllScatter(pxCenter + float2( i,  0), color);
+		onGfxForAllScatter(pxCenter+ float2(-i,  0), color);
+		onGfxForAllScatter(pxCenter+ float2( 0,  i), color);
+		onGfxForAllScatter(pxCenter + float2( 0, -i), color);
+	}
+}
+
+void s2h_printTxt(inout ContextScatter ui, uint a)
+{
+	s2h_printCharacter(ui, a); 
+}
+// glsl has no default arguments to we implement multiple functions instead making porting easier
+void s2h_printTxt(inout ContextScatter ui, uint a, uint b)
+{ s2h_printTxt(ui, a); s2h_printCharacter(ui, b); }
+void s2h_printTxt(inout ContextScatter ui, uint a, uint b, uint c)
+{ s2h_printTxt(ui, a, b); s2h_printCharacter(ui, c); }
+void s2h_printTxt(inout ContextScatter ui, uint a, uint b, uint c, uint d)
+{ s2h_printTxt(ui, a, b, c); s2h_printCharacter(ui, d); }
+void s2h_printTxt(inout ContextScatter ui, uint a, uint b, uint c, uint d, uint e)
+{ s2h_printTxt(ui, a, b, c, d); s2h_printCharacter(ui, e); }
+void s2h_printTxt(inout ContextScatter ui, uint a, uint b, uint c, uint d, uint e, uint f)
+{ s2h_printTxt(ui, a, b, c, d, e); s2h_printCharacter(ui, f); }
+
+void s2h_printLF(inout ContextScatter ui)
+{
+	ui.pxCursor.x = ui.pxLeftX;
+	ui.pxCursor.y += 8 * ui.scale;
+}
+
+void s2h_printInt(inout ContextScatter ui, int value)
+{
+	// leading '-'
+	if (value < 0)
+	{
+		s2h_printCharacter(ui, '-');
+		value = -value;
+	}
+	if (value == 0)
+	{
+		s2h_printCharacter(ui, '0');
+		return;
+	}
+	// move to right depending on number length
+	{
+		uint tmp = (uint)value;
+		while (tmp != 0u)
+		{
+			ui.pxCursor.x += 8 * ui.scale;
+			tmp /= 10u;
+		}
+	}
+	// digits
+	{
+		float backup = ui.pxCursor.x;
+		uint tmp = (uint)value;
+		while (tmp != 0u)
+		{
+			// 0..9
+			uint digit = tmp % 10u;
+			tmp /= 10u;
+			// go backwards
+			ui.pxCursor.x -= 8 * ui.scale;
+			s2h_printCharacter(ui, '0' + digit);
+			// counter +=8 from printCharacter ()
+			ui.pxCursor.x -= 8 * ui.scale;
+		}
+		ui.pxCursor.x = backup;
+	}
+}
+
+void s2h_printHex(inout ContextScatter ui, uint value)
+{
+	// 8 nibbles
+	for(int i = 7; i >= 0; --i)
+	{
+		// 0..15
+		uint nibble = (value >> (i * 4)) & 0xf;
+		uint start = (nibble < 10) ? '0' : ('A' - 10);
+		s2h_printCharacter(ui, start + nibble);
+	}
+}
+
+void s2h_printFloat(inout ContextScatter ui, float value)
+{
+	s2h_printInt(ui, int(value));
+	float fractional = frac(abs(value));
+
+	s2h_printCharacter(ui, '.');
+
+	uint digitCount = 3u;
+
+	// todo: unit tests, this is likely wrong at lower precision
+
+	// fractional digits
+	for(uint i = 0u; i < digitCount; ++i)
+	{
+		fractional *= 10.0f;
+		// 0..9
+		uint digit = uint(fractional);
+		fractional = frac(fractional);
+		s2h_printCharacter(ui, '0' + digit);
+	}
+}
+
+void s2h_printBlock(inout ContextScatter ui, float4 color)
+{
+	[loop] for(int y = 0; y < 8 * ui.scale; ++y)
+	[loop] for(int x = 0; x < 8 * ui.scale; ++x)
+	{
+		float2 pxLocal = (float2(x, y) ) / ui.scale - float2(3.5f, 3.5f);
+
+		float mask = saturate(4 - max(abs(pxLocal.x), abs(pxLocal.y)));
+
+		if(mask)
+			onGfxForAllScatter(ui.pxCursor + int2(x,y), color);
+	}
+
+	ui.pxCursor.x += 8 * ui.scale;
+}
+
+void s2h_printDisc(inout ContextScatter ui, float4 color)
+{
+	[loop] for(int y = 0; y < 8 * ui.scale; ++y)
+	[loop] for(int x = 0; x < 8 * ui.scale; ++x)
+	{
+		float2 pxLocal = (float2(x, y) ) / ui.scale - float2(3.5f, 3.5f);
+
+		float mask = saturate(4 - length(pxLocal));
+
+		if(mask)
+			onGfxForAllScatter(ui.pxCursor + int2(x,y), color);
+	}
+
+	ui.pxCursor.x += 8 * ui.scale;
+}
+
+#endif // S2H_SCATTER_INCLUDE

src/Runtime/Ghost.Graphics/Utilities/MeshletUtility.cs

@@ -1,4 +1,6 @@
-using Ghost.Graphics.Core;
+// Source: https://github.com/zeux/meshoptimizer/blob/master/demo/clusterlod.h
+// Translated from C++ to C#.
+
 using Ghost.MeshOptimizer;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
@@ -172,9 +174,9 @@ public static unsafe class MeshletUtility
         };
     }
 
-    private static ClodBounds MergeBounds(UnsafeList<Cluster> clusters, UnsafeList<int> group)
+    private static ClodBounds MergeBounds(UnsafeList<Cluster> clusters, UnsafeList<int> group, AllocationHandle handle)
     {
-        using var boundsList = new UnsafeArray<ClodBounds>(group.Count, Allocator.FreeList);
+        using var boundsList = new UnsafeArray<ClodBounds>(group.Count, handle);
         for (var j = 0; j < group.Count; j++)
         {
             boundsList[j] = (clusters[group[j]].bounds);
@@ -202,13 +204,13 @@ public static unsafe class MeshletUtility
         };
     }
 
-    private static UnsafeList<Cluster> Clusterize(ref readonly ClodConfig config, ref readonly ClodMesh mesh, uint* indices, nuint indexCount, Allocator allocator)
+    private static UnsafeList<Cluster> Clusterize(ref readonly ClodConfig config, ref readonly ClodMesh mesh, uint* indices, nuint indexCount, AllocationHandle handle)
     {
         var maxMeshlets = MeshOptApi.BuildMeshletsBound(indexCount, config.maxVertices, config.minTriangles);
 
-        using var meshlets = new UnsafeArray<meshopt_Meshlet>((int)maxMeshlets, Allocator.FreeList);
+        using var meshlets = new UnsafeArray<meshopt_Meshlet>((int)maxMeshlets, handle);
-        using var meshletVertices = new UnsafeArray<uint>((int)indexCount, Allocator.FreeList);
+        using var meshletVertices = new UnsafeArray<uint>((int)indexCount, handle);
-        using var meshletTriangles = new UnsafeArray<byte>((int)indexCount, Allocator.FreeList);
+        using var meshletTriangles = new UnsafeArray<byte>((int)indexCount, handle);
 
         var pMeshlets = (meshopt_Meshlet*)meshlets.GetUnsafePtr();
         var pMeshletVertices = (uint*)meshletVertices.GetUnsafePtr();
@@ -236,7 +238,7 @@ public static unsafe class MeshletUtility
             );
         }
 
-        var clusters = new UnsafeList<Cluster>((int)meshletCount, allocator);
+        var clusters = new UnsafeList<Cluster>((int)meshletCount, handle);
 
         for (nuint i = 0; i < meshletCount; i++)
         {
@@ -255,9 +257,9 @@ public static unsafe class MeshletUtility
             var cluster = new Cluster
             {
                 vertices = meshlet.vertex_count,
-                indices = new UnsafeList<uint>((int)(meshlet.triangle_count * 3), Allocator.FreeList),
+                indices = new UnsafeList<uint>((int)(meshlet.triangle_count * 3), handle),
-                uniqueVertices = new UnsafeList<uint>((int)meshlet.vertex_count, Allocator.FreeList),
+                uniqueVertices = new UnsafeList<uint>((int)meshlet.vertex_count, handle),
-                localIndices = new UnsafeList<byte>((int)(meshlet.triangle_count * 3), Allocator.FreeList),
+                localIndices = new UnsafeList<byte>((int)(meshlet.triangle_count * 3), handle),
                 group = -1,
                 refined = -1
             };
@@ -324,12 +326,12 @@ public static unsafe class MeshletUtility
         }
     }
 
-    private static UnsafeList<UnsafeList<int>> Partition(ref readonly ClodConfig config, ref readonly ClodMesh mesh, UnsafeList<Cluster> clusters, UnsafeList<int> pending, UnsafeArray<uint> remap, Allocator allocator)
+    private static UnsafeList<UnsafeList<int>> Partition(ref readonly ClodConfig config, ref readonly ClodMesh mesh, UnsafeList<Cluster> clusters, UnsafeList<int> pending, UnsafeArray<uint> remap, AllocationHandle handle)
     {
         if (pending.Count <= (int)config.partitionSize)
         {
-            var single = new UnsafeList<UnsafeList<int>>(1, allocator);
+            var single = new UnsafeList<UnsafeList<int>>(1, handle);
-            var pendingcpy = new UnsafeList<int>(pending.Count, Allocator.FreeList);
+            var pendingcpy = new UnsafeList<int>(pending.Count, handle);
 
             pendingcpy.AddRange(pending.AsSpan());
             single.Add(pendingcpy);
@@ -343,8 +345,8 @@ public static unsafe class MeshletUtility
             totalIndexCount += (nuint)clusters[pending[i]].indices.Count;
         }
 
-        using var clusterIndices = new UnsafeList<uint>((int)totalIndexCount, Allocator.FreeList);
+        using var clusterIndices = new UnsafeList<uint>((int)totalIndexCount, handle);
-        using var clusterCounts = new UnsafeList<uint>(pending.Count, Allocator.FreeList);
+        using var clusterCounts = new UnsafeList<uint>(pending.Count, handle);
 
         nuint offset = 0;
         for (var i = 0; i < pending.Count; i++)
@@ -359,7 +361,7 @@ public static unsafe class MeshletUtility
             offset += (nuint)cluster.indices.Count;
         }
 
-        using var clusterPart = new UnsafeArray<uint>(pending.Count, Allocator.FreeList);
+        using var clusterPart = new UnsafeArray<uint>(pending.Count, handle);
 
         var partitionCount = MeshOptApi.PartitionClusters(
             (uint*)clusterPart.GetUnsafePtr(),
@@ -373,10 +375,10 @@ public static unsafe class MeshletUtility
             config.partitionSize
         );
 
-        var partitions = new UnsafeList<UnsafeList<int>>((int)partitionCount, allocator);
+        var partitions = new UnsafeList<UnsafeList<int>>((int)partitionCount, handle);
         for (nuint i = 0; i < partitionCount; i++)
         {
-            partitions.Add(new UnsafeList<int>((int)(config.partitionSize + config.partitionSize / 3), allocator));
+            partitions.Add(new UnsafeList<int>((int)(config.partitionSize + config.partitionSize / 3), handle));
         }
 
         for (var i = 0; i < pending.Count; i++)
@@ -387,9 +389,9 @@ public static unsafe class MeshletUtility
         return partitions;
     }
 
-    private static int OutputGroup(ref readonly ClodConfig config, ref readonly ClodMesh mesh, UnsafeList<Cluster> clusters, UnsafeList<int> group, ClodBounds simplified, int depth, void* outputContext, ClodOutputDelegate? outputCallback)
+    private static int OutputGroup(ref readonly ClodConfig config, ref readonly ClodMesh mesh, UnsafeList<Cluster> clusters, UnsafeList<int> group, ClodBounds simplified, int depth, void* outputContext, ClodOutputDelegate? outputCallback, AllocationHandle handle)
     {
-        using var groupClusters = new UnsafeList<ClodCluster>(group.Count, Allocator.FreeList);
+        using var groupClusters = new UnsafeList<ClodCluster>(group.Count, handle);
 
         for (var i = 0; i < group.Count; i++)
         {
@@ -423,10 +425,10 @@ public static unsafe class MeshletUtility
         public uint id;
     }
 
-    private static void SimplifyFallback(ref UnsafeArray<uint> lod, ref readonly ClodMesh mesh, ReadOnlyUnsafeCollection<uint> indices, ReadOnlyUnsafeCollection<byte> locks, nuint target_count, float* error)
+    private static void SimplifyFallback(ref UnsafeArray<uint> lod, ref readonly ClodMesh mesh, ReadOnlyUnsafeCollection<uint> indices, ReadOnlyUnsafeCollection<byte> locks, nuint target_count, float* error, AllocationHandle handle)
     {
-        using var subset = new UnsafeArray<SloppyVertex>(indices.Count, Allocator.FreeList);
+        using var subset = new UnsafeArray<SloppyVertex>(indices.Count, handle);
-        using var subset_locks = new UnsafeArray<byte>(indices.Count, Allocator.FreeList);
+        using var subset_locks = new UnsafeArray<byte>(indices.Count, handle);
 
         lod.Resize(indices.Count);
 
@@ -460,9 +462,9 @@ public static unsafe class MeshletUtility
         }
     }
 
-    public static UnsafeArray<uint> Simplify(ref readonly ClodConfig config, ref readonly ClodMesh mesh, ReadOnlyUnsafeCollection<uint> indices, ReadOnlyUnsafeCollection<byte> locks, nuint targetCount, float* error, Allocator allocator)
+    public static UnsafeArray<uint> Simplify(ref readonly ClodConfig config, ref readonly ClodMesh mesh, ReadOnlyUnsafeCollection<uint> indices, ReadOnlyUnsafeCollection<byte> locks, nuint targetCount, float* error, AllocationHandle handle)
     {
-        var lod = new UnsafeArray<uint>(indices.Count, allocator);
+        var lod = new UnsafeArray<uint>(indices.Count, handle);
 
         if (targetCount >= (nuint)indices.Count)
         {
@@ -527,7 +529,7 @@ public static unsafe class MeshletUtility
 
         if ((nuint)lod.Length > targetCount && config.simplifyFallbackSloppy)
         {
-            SimplifyFallback(ref lod, in mesh, indices, locks, targetCount, error);
+            SimplifyFallback(ref lod, in mesh, indices, locks, targetCount, error, handle);
             *error *= config.simplifyErrorFactorSloppy;
         }
 
@@ -575,8 +577,13 @@ public static unsafe class MeshletUtility
     {
         Debug.Assert(mesh.vertexAttributesStride % sizeof(float) == 0, "vertexAttributesStride must be a multiple of sizeof(float)");
 
-        using var locks = new UnsafeArray<byte>((int)mesh.vertexCount, Allocator.FreeList, AllocationOption.Clear);
+        using var pool = new MemoryPool<VirtualArena, VirtualArena.CreationOptions>(new VirtualArena.CreationOptions
-        using var remap = new UnsafeArray<uint>((int)mesh.vertexCount, Allocator.FreeList);
+        {
+            reserveCapacity = 256 * 1024 * 1024
+        });
+
+        using var locks = new UnsafeArray<byte>((int)mesh.vertexCount, pool.AllocationHandle, AllocationOption.Clear); ;
+        using var remap = new UnsafeArray<uint>((int)mesh.vertexCount, pool.AllocationHandle);
 
         MeshOptApi.GeneratePositionRemap((uint*)remap.GetUnsafePtr(), mesh.vertexPositions, mesh.vertexCount, mesh.vertexPositionsStride);
 
@@ -599,14 +606,14 @@ public static unsafe class MeshletUtility
             }
         }
 
-        using var clusters = Clusterize(in config, in mesh, mesh.indices, mesh.indexCount, Allocator.FreeList);
+        using var clusters = Clusterize(in config, in mesh, mesh.indices, mesh.indexCount, pool.AllocationHandle);
 
         for (var i = 0; i < clusters.Count; i++)
         {
             clusters[i].bounds = ComputeBounds(in mesh, clusters[i].indices, 0.0f);
         }
 
-        using var pending = new UnsafeList<int>(clusters.Count, Allocator.FreeList);
+        using var pending = new UnsafeList<int>(clusters.Count, pool.AllocationHandle);
         for (var i = 0; i < clusters.Count; i++)
         {
             pending.Add(i);
@@ -616,14 +623,14 @@ public static unsafe class MeshletUtility
 
         while (pending.Count > 1)
         {
-            using var groups = Partition(in config, in mesh, clusters, pending, remap, Allocator.FreeList);
+            using var groups = Partition(in config, in mesh, clusters, pending, remap, pool.AllocationHandle);
             pending.Clear();
 
             LockBoundary(locks, groups, clusters, remap, mesh.vertexLock);
 
             for (var i = 0; i < groups.Count; i++)
             {
-                using var merged = new UnsafeList<uint>(groups[i].Count * (int)config.maxTriangles * 3, Allocator.FreeList);
+                using var merged = new UnsafeList<uint>(groups[i].Count * (int)config.maxTriangles * 3, pool.AllocationHandle);
                 for (var j = 0; j < groups[i].Count; j++)
                 {
                     var clusterIndices = clusters[groups[i][j]].indices;
@@ -631,28 +638,28 @@ public static unsafe class MeshletUtility
                 }
 
                 var targetSize = (nuint)(merged.Count / 3 * config.simplifyRatio * 3.0f);
-                var bounds = MergeBounds(clusters, groups[i]);
+                var bounds = MergeBounds(clusters, groups[i], pool.AllocationHandle);
 
                 var error = 0.0f;
-                using var simplified = Simplify(in config, in mesh, merged.AsReadOnly(), locks.AsReadOnly(), targetSize, &error, Allocator.FreeList);
+                using var simplified = Simplify(in config, in mesh, merged.AsReadOnly(), locks.AsReadOnly(), targetSize, &error, pool.AllocationHandle);
 
                 if ((nuint)simplified.Length > (nuint)(merged.Count * config.simplifyThreshold))
                 {
                     bounds.error = float.MaxValue;
-                    OutputGroup(in config, in mesh, clusters, groups[i], bounds, depth, outputContext, outputCallback);
+                    OutputGroup(in config, in mesh, clusters, groups[i], bounds, depth, outputContext, outputCallback, pool.AllocationHandle);
                     continue;
                 }
 
                 bounds.error = Math.Max(bounds.error * config.simplifyErrorMergePrevious, error) + error * config.simplifyErrorMergeAdditive;
 
-                var refined = OutputGroup(in config, in mesh, clusters, groups[i], bounds, depth, outputContext, outputCallback);
+                var refined = OutputGroup(in config, in mesh, clusters, groups[i], bounds, depth, outputContext, outputCallback, pool.AllocationHandle);
                 
                 for (var j = 0; j < groups[i].Count; j++)
                 {
                     clusters[groups[i][j]].Dispose();
                 }
 
-                using var split = Clusterize(in config, in mesh, (uint*)simplified.GetUnsafePtr(), (nuint)simplified.Length, Allocator.FreeList);
+                using var split = Clusterize(in config, in mesh, (uint*)simplified.GetUnsafePtr(), (nuint)simplified.Length, pool.AllocationHandle);
                 for (var j = 0; j < split.Count; j++)
                 {
                     split[j].refined = refined;
@@ -674,7 +681,7 @@ public static unsafe class MeshletUtility
         {
             var bounds = clusters[pending[0]].bounds;
             bounds.error = float.MaxValue;
-            OutputGroup(in config, in mesh, clusters, pending, bounds, depth, outputContext, outputCallback);
+            OutputGroup(in config, in mesh, clusters, pending, bounds, depth, outputContext, outputCallback, pool.AllocationHandle);
         }
 
         var finalClusterCount = (nuint)clusters.Count;

src/Runtime/Ghost.Graphics/test.gshdr

@@ -53,11 +53,11 @@ shader "MyShader/Standard"
                 MeshData meshData = LoadData<MeshData>(instanceData.meshBuffer, 0);
 
                 ByteAddressBuffer meshletBuffer = GET_BUFFER(meshData.meshletBuffer);
-                Meshlet m = meshletBuffer.Load<Meshlet>(groupID.x * sizeof(Meshlet));
+                Meshlet meshlet = meshletBuffer.Load<Meshlet>(groupID.x * sizeof(Meshlet));
 
                 s_Payload.meshletIndex = groupID.x;
 
-                uint lodLevel = (m.packedCounts >> 24) & 0xFFu;
+                uint lodLevel = (meshlet.packedCounts >> 24) & 0xFFu;
                 uint emitMeshlet = lodLevel == 0u ? 1u : 0u;
                 DispatchMesh(emitMeshlet, 1u, 1u, s_Payload);
             }
@@ -74,10 +74,10 @@ shader "MyShader/Standard"
                 MeshData meshData = LoadData<MeshData>(instanceData.meshBuffer, 0);
 
                 ByteAddressBuffer meshletBuffer = GET_BUFFER(meshData.meshletBuffer);
-                Meshlet m = meshletBuffer.Load<Meshlet>(meshPayload.meshletIndex * sizeof(Meshlet));
+                Meshlet meshlet = meshletBuffer.Load<Meshlet>(meshPayload.meshletIndex * sizeof(Meshlet));
 
-                uint vertexCount = m.packedCounts & 0xFFu;
+                uint vertexCount = meshlet.packedCounts & 0xFFu;
-                uint triangleCount = (m.packedCounts >> 8) & 0xFFu;
+                uint triangleCount = (meshlet.packedCounts >> 8) & 0xFFu;
                 SetMeshOutputCounts(vertexCount, triangleCount);
 
                 ByteAddressBuffer meshletVerticesBuffer = GET_BUFFER(meshData.meshletVerticesBuffer);
@@ -86,7 +86,7 @@ shader "MyShader/Standard"
                 // Write vertex output
                 if (groupThreadID.x < vertexCount)
                 {
-                    uint vertexIndex = meshletVerticesBuffer.Load((m.vertexOffset + groupThreadID.x) * 4);
+                    uint vertexIndex = meshletVerticesBuffer.Load((meshlet.vertexOffset + groupThreadID.x) * 4);
                     ByteAddressBuffer vertices = GET_BUFFER(meshData.vertexBuffer);
                     Vertex v = vertices.Load<Vertex>(vertexIndex * sizeof(Vertex));
 
@@ -112,7 +112,7 @@ shader "MyShader/Standard"
                     uint triangleIndex = groupThreadID.x;
 
                     // Load the packed 32-bit integer containing the 3 local indices
-                    uint packedIndices = meshletTrianglesBuffer.Load((m.triangleOffset + triangleIndex) * 4);
+                    uint packedIndices = meshletTrianglesBuffer.Load((meshlet.triangleOffset + triangleIndex) * 4);
 
                     uint i0 = packedIndices & 0xFF;
                     uint i1 = (packedIndices >> 8) & 0xFF;

src/Test/Ghost.Graphics.Test/RenderPasses/TestRenderPipeline.cs

@@ -141,9 +141,9 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                 continue;
             }
 
-            Handle<GPUResource> instanceBufferHandle = default;
+            Handle<GPUBuffer> instanceBufferHandle = default;
-            Handle<GPUResource> viewBufferHandle = default;
+            Handle<GPUBuffer> viewBufferHandle = default;
-            Handle<GPUResource> frameBufferHandle = default;
+            Handle<GPUBuffer> frameBufferHandle = default;
 
             try
             {
@@ -220,17 +220,16 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                 //var frustum = CreateFrustum(request.view.nearClipPlane, request.view.farClipPlane, vp, viewDir, viewPos);
 
                 var instanceDataSize = (uint)(instanceCount * sizeof(InstanceData));
-                var instanceBufferDesc = ResourceDesc.Buffer(new BufferDesc
+                var instanceBufferDesc = new BufferDesc
                 {
                     Size = instanceDataSize,
                     Stride = (uint)sizeof(InstanceData),
                     Usage = BufferUsage.Raw | BufferUsage.ShaderResource,
                     MemoryType = ResourceMemoryType.Upload, // Upload directly for simplicity in testing
-                });
+                };
 
-                // TODO: Optimize by suballocation.
+                instanceBufferHandle = resourceManager.CreateTransientBuffer(in instanceBufferDesc, "Instance Buffer");
-                instanceBufferHandle = resourceManager.GetPooledResource(instanceBufferDesc);
+                var instanceBufferResource = instanceBufferHandle.AsResource();
-                var instanceBufferResource = instanceBufferHandle.AsGraphicsBuffer();
 
                 var instanceDataArray = new InstanceData[instanceCount];
                 var instanceIdx = 0;
@@ -256,21 +255,21 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                     };
                 }
 
-                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(instanceBufferHandle, null, BarrierSync.Copy, null, BarrierAccess.CopyDest));
+                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(instanceBufferResource, null, BarrierSync.Copy, null, BarrierAccess.CopyDest));
-                ctx.CommandBuffer.UploadBuffer(instanceBufferResource, instanceDataArray.AsSpan());
+                ctx.CommandBuffer.UploadBuffer(instanceBufferHandle, instanceDataArray.AsSpan());
-                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(instanceBufferHandle, BarrierSync.Copy, BarrierSync.AllShading, BarrierAccess.CopyDest, BarrierAccess.ShaderResource));
+                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(instanceBufferResource, BarrierSync.Copy, BarrierSync.AllShading, BarrierAccess.CopyDest, BarrierAccess.ShaderResource));
 
                 // 2. Allocate and populate View Data buffer
-                var viewDataSize = (uint)sizeof(ViewData);
+                var viewBufferDesc = new BufferDesc
-                var viewBufferDesc = ResourceDesc.Buffer(new BufferDesc
                 {
-                    Size = viewDataSize,
+                    Size = (uint)sizeof(ViewData),
-                    Stride = viewDataSize,
+                    Stride = (uint)sizeof(ViewData),
                     Usage = BufferUsage.Raw | BufferUsage.ShaderResource,
                     MemoryType = ResourceMemoryType.Upload,
-                });
+                };
 
-                viewBufferHandle = resourceManager.GetPooledResource(viewBufferDesc);
+                viewBufferHandle = resourceManager.CreateTransientBuffer(in viewBufferDesc, "View Buffer");
+                var viewBufferResource = viewBufferHandle.AsResource();
 
                 var viewData = new ViewData
                 {
@@ -283,31 +282,32 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                     screenSize = new float4(request.view.sensorSize.x, request.view.sensorSize.y, 1.0f / request.view.sensorSize.x, 1.0f / request.view.sensorSize.y)
                 };
 
-                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(viewBufferHandle, null, BarrierSync.Copy, null, BarrierAccess.CopyDest));
+                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(viewBufferResource, null, BarrierSync.Copy, null, BarrierAccess.CopyDest));
-                ctx.CommandBuffer.UploadBuffer(viewBufferHandle.AsGraphicsBuffer(), new ReadOnlySpan<ViewData>(in viewData));
+                ctx.CommandBuffer.UploadBuffer(viewBufferHandle, new ReadOnlySpan<ViewData>(in viewData));
-                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(viewBufferHandle, BarrierSync.Copy, BarrierSync.AllShading, BarrierAccess.CopyDest, BarrierAccess.ShaderResource));
+                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(viewBufferResource, BarrierSync.Copy, BarrierSync.AllShading, BarrierAccess.CopyDest, BarrierAccess.ShaderResource));
 
                 // 3. Allocate and populate Global Frame Data buffer
                 var frameDataSize = (uint)sizeof(FrameData);
-                var frameBufferDesc = ResourceDesc.Buffer(new BufferDesc
+                var frameBufferDesc = new BufferDesc
                 {
                     Size = frameDataSize,
                     Stride = frameDataSize,
                     Usage = BufferUsage.Raw | BufferUsage.ShaderResource,
                     MemoryType = ResourceMemoryType.Upload,
-                });
+                };
 
-                frameBufferHandle = resourceManager.GetPooledResource(frameBufferDesc);
+                frameBufferHandle = resourceManager.CreateTransientBuffer(in frameBufferDesc, "Frame Buffer");
+                var frameBufferResource = frameBufferHandle.AsResource();
 
                 var frameData = new FrameData
                 {
-                    viewBufferIndex = resourceDatabase.GetBindlessIndex(viewBufferHandle),
+                    viewBufferIndex = resourceDatabase.GetBindlessIndex(viewBufferResource),
-                    instanceBufferIndex = resourceDatabase.GetBindlessIndex(instanceBufferResource.AsResource()),
+                    instanceBufferIndex = resourceDatabase.GetBindlessIndex(instanceBufferResource),
                 };
 
-                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(frameBufferHandle, null, BarrierSync.Copy, null, BarrierAccess.CopyDest));
+                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(frameBufferResource, null, BarrierSync.Copy, null, BarrierAccess.CopyDest));
-                ctx.CommandBuffer.UploadBuffer(frameBufferHandle.AsGraphicsBuffer(), new ReadOnlySpan<FrameData>(in frameData));
+                ctx.CommandBuffer.UploadBuffer(frameBufferHandle, new ReadOnlySpan<FrameData>(in frameData));
-                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(frameBufferHandle, BarrierSync.Copy, BarrierSync.AllShading, BarrierAccess.CopyDest, BarrierAccess.ShaderResource));
+                ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(frameBufferResource, BarrierSync.Copy, BarrierSync.AllShading, BarrierAccess.CopyDest, BarrierAccess.ShaderResource));
 
                 if (request.renderFunc != null)
                 {
@@ -320,7 +320,9 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                     var backBuffer = _renderGraph.ImportTexture(rt, "BackBuffer");
 
                     MeshletDebugPass(backBuffer, request.opaqueRenderList, 
-                        resourceDatabase.GetBindlessIndex(frameBufferHandle), resourceDatabase.GetBindlessIndex(viewBufferHandle), resourceDatabase.GetBindlessIndex(instanceBufferHandle));
+                        resourceDatabase.GetBindlessIndex(frameBufferResource),
+                        resourceDatabase.GetBindlessIndex(viewBufferResource),
+                        resourceDatabase.GetBindlessIndex(instanceBufferResource));
 
                     var viewState = new ViewState(rtSize.x, rtSize.y, rtSize.x, rtSize.y);
                     _renderGraph.Compile(viewState);
@@ -329,10 +331,9 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
             }
             finally
             {
-                // We must enqueue a return for the pooled resources so they are freed next frame.
+                _renderSystem.GraphicsEngine.ResourceDatabase.ReleaseResource(instanceBufferHandle.AsResource());
-                resourceManager.ReturnPooledResource(instanceBufferHandle);
+                _renderSystem.GraphicsEngine.ResourceDatabase.ReleaseResource(viewBufferHandle.AsResource());
-                resourceManager.ReturnPooledResource(viewBufferHandle);
+                _renderSystem.GraphicsEngine.ResourceDatabase.ReleaseResource(frameBufferHandle.AsResource());
-                resourceManager.ReturnPooledResource(frameBufferHandle);
 
                 if (request.swapChainIndex >= 0)
                 {

src/Test/Ghost.Graphics.Test/Utilities/MeshUtility.cs

@@ -67,7 +67,6 @@ internal static class MeshUtility
         }
 
         using var flatVertices = new UnsafeList<Vertex>(1024, scope0.AllocationHandle);
-        //using var flatIndices = new UnsafeList<uint>(1024, scope0.AllocationHandle);
 
         var needComputeNormals = false;
 
@@ -91,7 +90,7 @@ internal static class MeshUtility
 
                 var maxScratchIndices = (int)(pMesh->max_face_triangles * 3u);
 
-                using var triIndicesArray = new UnsafeArray<uint>(maxScratchIndices, scope1.AllocationHandle);
+                var triIndicesArray = new UnsafeArray<uint>(maxScratchIndices, scope1.AllocationHandle);
 
                 for (var j = 0u; j < pMesh->num_faces; j++)
                 {

src/Test/Ghost.Graphics.Test/Windows/GraphicsTestWindow.xaml.cs

@@ -5,7 +5,6 @@ using Ghost.Engine.Utilities;
 using Ghost.Entities;
 using Ghost.Graphics.Core;
 using Ghost.Graphics.RHI;
-using Ghost.Graphics.Utilities;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Media;