Tutorial 27: use PrefilteredCubeLastMip to sample environment map

Author: TheMostDiligent

Tutorials/Tutorial27_PostProcessing/assets/shaders/ComputeLighting.fx

@@ -77,7 +77,7 @@ float3 ComputeSpecularIBL(float2 Location, float3 F0, float3 N, float3 V, float
     float3 R = reflect(-V, N);
     float2 BRDF_LUT = SampleBRDFIntegrationMap(float2(NdotV, Roughness));
     float4 SSR = g_TextureSSR.Load(int3(Location, 0));
-    float3 T1 = SamplePrefilteredEnvironmentMap(R, Roughness * g_PBRRendererAttibs.PrefilteredCubeMipLevels);
+    float3 T1 = SamplePrefilteredEnvironmentMap(R, Roughness * g_PBRRendererAttibs.PrefilteredCubeLastMip);
     float3 T2 = (F0 * BRDF_LUT.x + BRDF_LUT.yyy);
     return lerp(T1, SSR.rgb, SSR.w * g_Camera.f4ExtraData[0].w) * T2;
 }

Tutorials/Tutorial27_PostProcessing/readme.md

@@ -233,7 +233,7 @@ float3 ComputeSpecularIBL(float2 Location, float3 F0, float3 N, float3 V, float
     float3 R = reflect(-V, N);
     float2 BRDF_LUT = SampleBRDFIntegrationMap(float2(NdotV, Roughness));
     float4 SSR = g_TextureSSR.Load(int3(Location, 0));
-    float3 T1 = SamplePrefilteredEnvironmentMap(R, Roughness * g_PBRRendererAttibs.PrefilteredCubeMipLevels); 
+    float3 T1 = SamplePrefilteredEnvironmentMap(R, Roughness * g_PBRRendererAttibs.PrefilteredCubeLastMip); 
     float3 T2 = (F0 * BRDF_LUT.x + BRDF_LUT.yyy);
     return lerp(T1, SSR.rgb, SSR.w) * T2;
 }

Tutorials/Tutorial27_PostProcessing/src/Tutorial27_PostProcessing.cpp

@@ -193,12 +193,12 @@ void Tutorial27_PostProcessing::Initialize(const SampleInitInfo& InitInfo)
     m_ScreenSpaceReflection = std::make_unique<ScreenSpaceReflection>(m_pDevice);
     m_ShaderParams          = std::make_unique<ShaderParams>();
 
-    m_ShaderParams->PBRRenderParams.OcclusionStrength        = 1.0f;
-    m_ShaderParams->PBRRenderParams.IBLScale                 = 1.0f;
-    m_ShaderParams->PBRRenderParams.AverageLogLum            = 0.2f;
-    m_ShaderParams->PBRRenderParams.WhitePoint               = HLSL::ToneMappingAttribs{}.fWhitePoint;
-    m_ShaderParams->PBRRenderParams.MiddleGray               = HLSL::ToneMappingAttribs{}.fMiddleGray;
-    m_ShaderParams->PBRRenderParams.PrefilteredCubeMipLevels = static_cast<float>(m_Resources[RESOURCE_IDENTIFIER_PREFILTERED_ENVIRONMENT_MAP].AsTexture()->GetDesc().MipLevels - 1.0);
+    m_ShaderParams->PBRRenderParams.OcclusionStrength      = 1.0f;
+    m_ShaderParams->PBRRenderParams.IBLScale               = 1.0f;
+    m_ShaderParams->PBRRenderParams.AverageLogLum          = 0.2f;
+    m_ShaderParams->PBRRenderParams.WhitePoint             = HLSL::ToneMappingAttribs{}.fWhitePoint;
+    m_ShaderParams->PBRRenderParams.MiddleGray             = HLSL::ToneMappingAttribs{}.fMiddleGray;
+    m_ShaderParams->PBRRenderParams.PrefilteredCubeLastMip = static_cast<float>(m_Resources[RESOURCE_IDENTIFIER_PREFILTERED_ENVIRONMENT_MAP].AsTexture()->GetDesc().MipLevels - 1);
 
     m_ShaderParams->SSRSettings.MaxTraversalIntersections = 64;
     m_ShaderParams->SSRSettings.DepthBufferThickness      = 0.15f;