Fixed maxRecursionDepth bug that caused hanging

Author: chauvuha

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraForestSER/D3D12RaytracingSakuraForestSER.cpp

@@ -38,7 +38,7 @@ const wchar_t* D3D12RaytracingSakuraForestSER::c_floorClosestHitShaderName = L"F
 const wchar_t* D3D12RaytracingSakuraForestSER::c_trunkClosestHitShaderName = L"TrunkClosestHitShader";
 const wchar_t* D3D12RaytracingSakuraForestSER::c_leavesClosestHitShaderName = L"LeavesClosestHitShader";
 const wchar_t* D3D12RaytracingSakuraForestSER::c_bushClosestHitShaderName = L"BushClosestHitShader";
-const wchar_t* D3D12RaytracingSakuraForestSER::c_tcubeClosestHitShaderName = L"TCubeClosestHitShader";
+const wchar_t* D3D12RaytracingSakuraForestSER::c_refCubeClosestHitShaderName = L"TCubeClosestHitShader";
 const wchar_t* D3D12RaytracingSakuraForestSER::c_missShaderName = L"MyMissShader";
 
 #define PRINT(text) OutputDebugStringA(text);
@@ -227,7 +227,7 @@ void D3D12RaytracingSakuraForestSER::InitializeScene()
         // Initialize the view and projection inverse matrices.
         // m_eye currently at the middle of the forest
         m_eye = { 0.0f, 2.2f, -2.0f, 1.0f };
-        m_at = { 1.0f, 1.65f, -6.0f, 1.0f };
+        m_at = { 1.0f, 2.5f, -6.0f, 1.0f };
         XMVECTOR right = { 1.0f, 0.0f, 0.0f, 0.0f };
 
         XMVECTOR direction = XMVector4Normalize(m_at - m_eye);
@@ -596,7 +596,7 @@ void D3D12RaytracingSakuraForestSER::CreateRaytracingPipelineStateObject()
         lib->DefineExport(c_trunkClosestHitShaderName);
         lib->DefineExport(c_leavesClosestHitShaderName);
         lib->DefineExport(c_bushClosestHitShaderName);
-        lib->DefineExport(c_tcubeClosestHitShaderName);
+        lib->DefineExport(c_refCubeClosestHitShaderName);
         lib->DefineExport(c_missShaderName);
     }
 
@@ -623,10 +623,10 @@ void D3D12RaytracingSakuraForestSER::CreateRaytracingPipelineStateObject()
     bushHitGroup->SetHitGroupExport(c_bushHitGroupName);
     bushHitGroup->SetHitGroupType(D3D12_HIT_GROUP_TYPE_TRIANGLES);
 
-    auto tcubeHitGroup = raytracingPipeline.CreateSubobject<CD3DX12_HIT_GROUP_SUBOBJECT>();
-    tcubeHitGroup->SetClosestHitShaderImport(c_tcubeClosestHitShaderName);
-    tcubeHitGroup->SetHitGroupExport(c_reflectiveCubeHitGroupName);
-    tcubeHitGroup->SetHitGroupType(D3D12_HIT_GROUP_TYPE_TRIANGLES);
+    auto refCubeHitGroup = raytracingPipeline.CreateSubobject<CD3DX12_HIT_GROUP_SUBOBJECT>();
+    refCubeHitGroup->SetClosestHitShaderImport(c_refCubeClosestHitShaderName);
+    refCubeHitGroup->SetHitGroupExport(c_reflectiveCubeHitGroupName);
+    refCubeHitGroup->SetHitGroupType(D3D12_HIT_GROUP_TYPE_TRIANGLES);
 
     // Shader config
    //  Defines the maximum sizes in bytes for the ray payload and attribute structure.
@@ -1258,7 +1258,7 @@ void D3D12RaytracingSakuraForestSER::BuildShaderTables()
     void* trunkHitGroupShaderIdentifier;
     void* leavesHitGroupShaderIdentifier;
     void* bushHitGroupShaderIdentifier;
-    void* tcubeHitGroupShaderIdentifier;
+    void* refCubeHitGroupShaderIdentifier;
 
     auto GetShaderIdentifiers = [&](auto* stateObjectProperties)
     {
@@ -1268,7 +1268,7 @@ void D3D12RaytracingSakuraForestSER::BuildShaderTables()
         trunkHitGroupShaderIdentifier = stateObjectProperties->GetShaderIdentifier(c_trunkHitGroupName);
         leavesHitGroupShaderIdentifier = stateObjectProperties->GetShaderIdentifier(c_leavesHitGroupName);
         bushHitGroupShaderIdentifier = stateObjectProperties->GetShaderIdentifier(c_bushHitGroupName);
-        tcubeHitGroupShaderIdentifier = stateObjectProperties->GetShaderIdentifier(c_reflectiveCubeHitGroupName);
+        refCubeHitGroupShaderIdentifier = stateObjectProperties->GetShaderIdentifier(c_reflectiveCubeHitGroupName);
     };
 
     // Get shader identifiers.
@@ -1338,7 +1338,7 @@ void D3D12RaytracingSakuraForestSER::BuildShaderTables()
             argument.cb = m_reflectiveCubeCB;
             argument.cb.albedo = XMFLOAT4(1.0f, 1.0f, 1.0f, 1.0f); 
             argument.cb.materialID = 1;
-            hitGroupShaderTable.push_back(ShaderRecord(tcubeHitGroupShaderIdentifier, shaderIdentifierSize, &argument, sizeof(argument)));
+            hitGroupShaderTable.push_back(ShaderRecord(refCubeHitGroupShaderIdentifier, shaderIdentifierSize, &argument, sizeof(argument)));
         }
 
         // Tree trunk shader records

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraForestSER/D3D12RaytracingSakuraForestSER.h

@@ -158,7 +158,7 @@ class D3D12RaytracingSakuraForestSER : public DXSample
     static const wchar_t* c_floorClosestHitShaderName;
     static const wchar_t* c_trunkClosestHitShaderName;
     static const wchar_t* c_leavesClosestHitShaderName;
-    static const wchar_t* c_tcubeClosestHitShaderName;
+    static const wchar_t* c_refCubeClosestHitShaderName;
     static const wchar_t* c_missShaderName;
     static const wchar_t* c_bushClosestHitShaderName;
     ComPtr<ID3D12Resource> m_missShaderTable;

Samples/Desktop/D3D12Raytracing/src/D3D12RaytracingSakuraForestSER/Raytracing.hlsl

@@ -15,6 +15,7 @@
 #define HLSL
 #include "RaytracingHlslCompat.h"
 #include "Star.hlsli"
+#define MAX_RECURSION_DEPTH 2
 
 using namespace dx;
 RaytracingAccelerationStructure Scene : register(t0, space0);
@@ -41,7 +42,6 @@ SamplerState TrunkSampler : register(s0);
 Texture2D<float4> BushTexture : register(t10, space0);
 SamplerState BushSampler : register(s1);
 
-    
 typedef BuiltInTriangleIntersectionAttributes MyAttributes;
 
 
@@ -166,7 +166,7 @@ void MyRaygenShader()
     ray.TMax = 10000.0;
 
     // Initialize payload
-    RayPayload payload = { float4(0, 0, 0, 0), 0, 0 };
+    RayPayload payload = { float4(0, 0, 0, 0), 1, 0 };
 
     if (g_sceneCB.sortMode == SORTMODE_OFF)
     {
@@ -190,8 +190,6 @@ void MyRaygenShader()
     RenderTarget[DispatchRaysIndex().xy] = payload.color;
 }
 
-
-
 
 // Fresnel reflectance - schlick approximation.
 float3 FresnelReflectanceSchlick(in float3 I, in float3 N, in float3 f0)
@@ -211,7 +209,8 @@ struct Ray
 // Trace a radiance ray into the scene and returns a shaded color. 
 float4 TraceRadianceRay(in Ray ray, in int currentRayRecursionDepth)
 {
-    if (currentRayRecursionDepth >= 1)
+    // Stop tracing if maximum depth is reached.
+    if (currentRayRecursionDepth >= MAX_RECURSION_DEPTH)
     {
         return float4(0, 0, 0, 0);
     }
@@ -220,8 +219,7 @@ float4 TraceRadianceRay(in Ray ray, in int currentRayRecursionDepth)
     RayDesc rayDesc;
     rayDesc.Origin = ray.Origin;
     rayDesc.Direction = ray.Direction;
-    // Set TMin to a zero value to avoid aliasing artifacts along contact areas.
-    // Note: make sure to enable face culling so as to avoid surface face fighting.
+    // Set TMin to a non-zero small value to avoid aliasing issues due to floating - point errors.
     rayDesc.TMin = 0.001;
     rayDesc.TMax = 10000;
     RayPayload rayPayload = { float4(0, 0, 0, 0), currentRayRecursionDepth + 1, 0 };
@@ -259,7 +257,7 @@ void FloorClosestHitShader(inout RayPayload payload, in MyAttributes attr)
     float3 finalColor;
 
     // Trace reflection ray if surface is dark
-    if (all(sampled.rgb < 0.1) && payload.recursionDepth < 2)
+    if (all(sampled.rgb < 0.1) && payload.recursionDepth < MAX_RECURSION_DEPTH)
     {
         Ray reflectionRay;
         reflectionRay.Origin = hitPosition + triangleNormal * 0.001f;
@@ -426,7 +424,6 @@ void TCubeClosestHitShader(inout RayPayload payload, in MyAttributes attr)
 [shader("miss")]
 void MyMissShader(inout RayPayload payload)
 {
-    //float4 background = float4(1.0000f, 0.9216f, 0.9373f, 1.0f);
     float4 background = float4(0.05f, 0.02f, 0.08f, 1.0f);
 
     // Create sky position and ray direction