Added mip selection using ray differentials

source/Algorithm/PathTracing.c

@@ -26,6 +26,7 @@ vec4s path_trace(const scene_t* scene, ray_t ray, uint32_t sample_index, uint16_
             {
                 .wo = active_ray.direction,
                 .textures = &scene->textures,
+                .spread_angle = active_ray.spread_angle,
             };
             path_output sky_output = evaluate_bsdf_sky(&scene->lights, &light_context, throughput, sample_index);
 
@@ -48,6 +49,10 @@ vec4s path_trace(const scene_t* scene, ray_t ray, uint32_t sample_index, uint16_
 
         uint8_t material_id = scene->triangles.buffer[closest_hit.triangle_id].material_id;
         const material_t* hit_material = &scene->materials.buffer[material_id];
+        
+        // Calculate ray cone width at the hit point
+        float current_cone_width = active_ray.width + closest_hit.distance * active_ray.spread_angle;
+
         shading_context_t shading_context =
         {
             .camera_position = scene->camera.position,
@@ -67,6 +72,10 @@ vec4s path_trace(const scene_t* scene, ray_t ray, uint32_t sample_index, uint16_
             .triangles = &scene->triangles,
             .lights = &scene->lights,
             .textures = &scene->textures,
+
+            .triangle_id = closest_hit.triangle_id,
+            .cone_width = current_cone_width,
+            .spread_angle = active_ray.spread_angle,
         };
 
         path_output material_output = render_material(hit_material, &shading_context);
@@ -105,15 +114,16 @@ vec4s path_trace(const scene_t* scene, ray_t ray, uint32_t sample_index, uint16_
 
         switch (material_output.state)
         {
-            case PS_TERMINATE:
-                goto end_path_trace;
             //case PATH_THROUGH:
             //    active_ray = ray_create(BIAS_RAY_ORIGION(closest_hit.point, glms_vec3_negate(closest_hit.normal)), active_ray.direction);
             //    continue;
-            default:
-                active_ray = ray_create(offset_ray_origin(closest_hit.point, closest_hit.normal, shading_context.wo), material_output.wi);
+            case PS_SUCCESS:
+                vec3s origin = offset_ray_origin(closest_hit.point, closest_hit.normal, shading_context.wo);
+                active_ray = ray_create(origin, material_output.wi, current_cone_width, material_output.spread_angle);
                 depth++;
                 break;
+            default:
+                goto end_path_trace;
         }
     }
 
@@ -151,6 +161,10 @@ void render_aov(const scene_t* scene, ray_t ray, uint32_t sample_index, uint16_t
         .triangles = &scene->triangles,
         .lights = &scene->lights,
         .textures = &scene->textures,
+
+        .triangle_id = closest_hit.triangle_id,
+        .cone_width = ray.width + closest_hit.distance * ray.spread_angle,
+        .spread_angle = ray.spread_angle,
     };
 
     render_material_aov(hit_material, &shading_context, aov_output);

source/Algorithm/RayIntersection.c

@@ -3,7 +3,7 @@
 #include "Geometry/Triangle.h"
 #include "cglm/struct/vec3.h"
 
-ray_t ray_create(vec3s origin, vec3s direction)
+ray_t ray_create(vec3s origin, vec3s direction, float cone_width, float spread_angle)
 {
     ray_t ray =
     {
@@ -13,7 +13,9 @@ ray_t ray_create(vec3s origin, vec3s direction)
         .sign =
         ((direction.x < 0.0f) ? 1 : 0) |
         ((direction.y < 0.0f) ? 2 : 0) |
-        ((direction.z < 0.0f) ? 4 : 0)
+        ((direction.z < 0.0f) ? 4 : 0),
+        .width = cone_width,
+        .spread_angle = spread_angle
     };
 
     ray.esp = glms_vec3_max(glms_vec3_abs(ray.origin)) * gamma(15);