Optimize ray tracing demo occlusion tracing

Author: kevyuu

71_RayTracingPipeline/app_resources/raytrace.rgen.hlsl

@@ -89,7 +89,7 @@ void main()
             rayDesc.TMin = 0.01;
             rayDesc.TMax = cLight.outLightDistance;
 
-            uint32_t shadowRayFlags = RAY_FLAG_ACCEPT_FIRST_HIT_AND_END_SEARCH | RAY_FLAG_FORCE_NON_OPAQUE | RAY_FLAG_SKIP_CLOSEST_HIT_SHADER;
+            uint32_t shadowRayFlags = RAY_FLAG_ACCEPT_FIRST_HIT_AND_END_SEARCH;
             OcclusionPayload occlusionPayload;
             occlusionPayload.attenuation = 1;
             TraceRay(topLevelAS, shadowRayFlags, 0xFF, ERT_OCCLUSION, 0, EMT_OCCLUSION, rayDesc, occlusionPayload);

71_RayTracingPipeline/app_resources/raytrace_shadow.rahit.hlsl

@@ -9,15 +9,6 @@ void main(inout OcclusionPayload payload, in BuiltInTriangleIntersectionAttribut
     const STriangleGeomInfo geom = vk::RawBufferLoad < STriangleGeomInfo > (pc.triangleGeomInfoBuffer + instID * sizeof(STriangleGeomInfo));
     const Material material = unpackMaterial(geom.material);
 
-    if (material.isTransparent())
-    {
-        payload.attenuation = material.alpha * payload.attenuation;
-        IgnoreHit();
-    }
-    else
-    {
-        payload.attenuation = 0;
-        AcceptHitAndEndSearch();
-    }
-
+    payload.attenuation = material.alpha * payload.attenuation;
+    IgnoreHit();
 }

71_RayTracingPipeline/app_resources/raytrace_shadow_triangle.rchit.hlsl

@@ -0,0 +1,7 @@
+#include "common.hlsl"
+
+[shader("closesthit")]
+void main(inout OcclusionPayload payload, in BuiltInTriangleIntersectionAttributes attribs)
+{
+    payload.attenuation = 0;
+}

71_RayTracingPipeline/main.cpp

@@ -164,6 +164,7 @@ class RaytracingPipelineApp final : public examples::SimpleWindowedApplication,
     const auto anyHitShaderShadowPayload = loadCompileAndCreateShader("app_resources/raytrace_shadow.rahit.hlsl");
     const auto missShader = loadCompileAndCreateShader("app_resources/raytrace.rmiss.hlsl");
     const auto shadowMissShader = loadCompileAndCreateShader("app_resources/raytrace_shadow.rmiss.hlsl");
+    const auto shadowClosestHitShader = loadCompileAndCreateShader("app_resources/raytrace_shadow_triangle.rchit.hlsl");
     const auto directionalLightCallShader = loadCompileAndCreateShader("app_resources/light_directional.rcall.hlsl");
     const auto pointLightCallShader = loadCompileAndCreateShader("app_resources/light_point.rcall.hlsl");
     const auto spotLightCallShader = loadCompileAndCreateShader("app_resources/light_spot.rcall.hlsl");
@@ -324,6 +325,7 @@ class RaytracingPipelineApp final : public examples::SimpleWindowedApplication,
         RTDS_RAYGEN,
         RTDS_MISS,
         RTDS_SHADOW_MISS,
+        RTDS_CLOSEST_HIT_SHADOW,
         RTDS_CLOSEST_HIT,
         RTDS_SPHERE_CLOSEST_HIT,
         RTDS_ANYHIT_PRIMARY,
@@ -339,6 +341,7 @@ class RaytracingPipelineApp final : public examples::SimpleWindowedApplication,
       shaders[RTDS_RAYGEN] = {.shader = raygenShader.get()};
       shaders[RTDS_MISS] = {.shader = missShader.get()};
       shaders[RTDS_SHADOW_MISS] = {.shader = shadowMissShader.get()};
+      shaders[RTDS_CLOSEST_HIT_SHADOW] = { .shader = shadowClosestHitShader.get() };
       shaders[RTDS_CLOSEST_HIT] = {.shader = closestHitShader.get()};
       shaders[RTDS_SPHERE_CLOSEST_HIT] = {.shader = proceduralClosestHitShader.get()};
       shaders[RTDS_ANYHIT_PRIMARY] = {.shader = anyHitShaderColorPayload.get()};
@@ -350,14 +353,15 @@ class RaytracingPipelineApp final : public examples::SimpleWindowedApplication,
 
       params.layout = pipelineLayout.get();
       params.shaders = std::span(shaders);
+      params.flags = IGPURayTracingPipeline::SCreationParams::FLAGS::NO_NULL_INTERSECTION_SHADERS;
 
       auto& shaderGroups = params.shaderGroups;
 
       shaderGroups.raygen = { .index = RTDS_RAYGEN };
 
       IRayTracingPipelineBase::SGeneralShaderGroup missGroups[EMT_COUNT];
       missGroups[EMT_PRIMARY] = { .index = RTDS_MISS };
-      missGroups[EMT_OCCLUSION] = { .index = RTDS_SHADOW_MISS };
+      missGroups[EMT_OCCLUSION] = { .index = IGPURayTracingPipeline::SGeneralShaderGroup::Unused };
       shaderGroups.misses = missGroups;
 
       auto getHitGroupIndex = [](E_GEOM_TYPE geomType, E_RAY_TYPE rayType)
@@ -370,6 +374,7 @@ class RaytracingPipelineApp final : public examples::SimpleWindowedApplication,
         .anyHit = RTDS_ANYHIT_PRIMARY,
       };
       hitGroups[getHitGroupIndex(EGT_TRIANGLES, ERT_OCCLUSION)] = {
+        .closestHit = RTDS_CLOSEST_HIT_SHADOW,
         .anyHit = RTDS_ANYHIT_SHADOW,
       };
       hitGroups[getHitGroupIndex(EGT_PROCEDURAL, ERT_PRIMARY)] = {
@@ -378,6 +383,7 @@ class RaytracingPipelineApp final : public examples::SimpleWindowedApplication,
         .intersectionShader = RTDS_INTERSECTION,
       };
       hitGroups[getHitGroupIndex(EGT_PROCEDURAL, ERT_OCCLUSION)] = {
+        .closestHit = RTDS_CLOSEST_HIT_SHADOW,
         .anyHit = RTDS_ANYHIT_SHADOW,
         .intersectionShader = RTDS_INTERSECTION,
       };