Initial Upload;

Runtime/Shader/Includes/VolumeSDF.hlsl

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+#ifndef VOLUME_SDF
+#define VOLUME_SDF
+
+#include "Packages/com.misaki.ao-volume/Runtime/Shader/Includes/VolumeData.cs.hlsl"
+
+float3 GetPositionLS(float4x4 inverseWorldMatrix, float3 positionWS)
+{
+    return mul(inverseWorldMatrix, float4(positionWS, 1.0)).xyz;
+}
+
+float BoxSDF(float3 positionWS, VolumeData data)
+{
+    float3 halfDim = data.size * 0.5;
+    
+    float3 positionLS = GetPositionLS(data.inverseWorldMatrix, positionWS);
+    
+    float3 d = halfDim - abs(positionLS);
+    float distToFace = min(d.x, min(d.y, d.z));
+    float maxDist = min(halfDim.x, min(halfDim.y, halfDim.z));
+    
+    return saturate(distToFace / maxDist);
+}
+
+float CapsuleSDF(float3 positionWS, VolumeData data)
+{
+    float3 positionLS = GetPositionLS(data.inverseWorldMatrix, positionWS);
+
+    float radius = data.size.x;
+    float length = data.size.y;
+    
+    // Define capsule along Y-axis in local space
+    float3 capsuleStart = float3(0, -length * 0.5, 0);
+    float3 capsuleEnd = float3(0, length * 0.5, 0);
+
+    // Compute SDF in local space
+    float3 dir = capsuleEnd - capsuleStart;
+    float lengthSq = dot(dir, dir);
+    float3 toPoint = positionLS - capsuleStart;
+    float projection = saturate(dot(toPoint, dir) / lengthSq);
+    float3 closestPoint = capsuleStart + projection * dir;
+    return distance(positionLS, closestPoint) - radius;
+}
+
+float EvaluateAOVolumeMask(VolumeData data, float3 positionWS, float3 normalWS)
+{
+    float volumeSDF = 1.0;
+    switch (data.volumeType)
+    {
+        case VOLUMETYPE_CAPSULE:
+            volumeSDF = CapsuleSDF(positionWS, data);
+            break;
+        case VOLUMETYPE_BOX:
+            volumeSDF = BoxSDF(positionWS, data);
+            break;
+    }
+    
+    return volumeSDF;
+}
+
+#endif