Add an option to disable shadow bias

Unity-Technologies · May 14, 2020 · 2dfeab2 · 2dfeab2
1 parent c6aa4cf
commit 2dfeab2
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Showing 2 changed files with 16 additions and 8 deletions.
diff --git a/com.unity.render-pipelines.high-definition/Runtime/Lighting/Shadow/HDShadowAlgorithms.hlsl b/com.unity.render-pipelines.high-definition/Runtime/Lighting/Shadow/HDShadowAlgorithms.hlsl
@@ -1,5 +1,9 @@
 // Configure which shadow algorithms to use per shadow level quality
 
+#ifndef SHADOW_USE_NORMAL_BIAS
+#define SHADOW_USE_NORMAL_BIAS 1 // Externally define as 0 to disable
+#endif
+
 // Since we use slope-scale bias, the constant bias is for now set as a small fixed value
 #define FIXED_UNIFORM_BIAS (1.0f / 65536.0f)
 
@@ -123,10 +127,12 @@ float3 EvalShadow_NormalBias(float worldTexelSize, float normalBias, float3 norm
 float EvalShadow_PunctualDepth(HDShadowData sd, Texture2D tex, SamplerComparisonState samp, float2 positionSS, float3 positionWS, float3 normalWS, float3 L, float L_dist, bool perspective)
 {
     positionWS = positionWS + sd.cacheTranslationDelta.xyz;
+#if SHADOW_USE_NORMAL_BIAS
     /* bias the world position */
     float worldTexelSize = EvalShadow_WorldTexelSize(sd.worldTexelSize, L_dist, true);
     float3 normalBias = EvalShadow_NormalBias(worldTexelSize, sd.normalBias, normalWS);
     positionWS += normalBias;
+#endif
     /* get shadowmap texcoords */
     float3 posTC = EvalShadow_GetTexcoordsAtlas(sd, _ShadowAtlasSize.zw, positionWS, perspective);
     /* sample the texture */
@@ -231,12 +237,12 @@ float EvalShadow_CascadedDepth_Blend(HDShadowContext shadowContext, Texture2D te
         HDShadowData sd = shadowContext.shadowDatas[index];
         LoadDirectionalShadowDatas(sd, shadowContext, index + shadowSplitIndex);
         positionWS = positionWS + sd.cacheTranslationDelta.xyz;
-
+    #if SHADOW_USE_NORMAL_BIAS
         /* normal based bias */
         float3 orig_pos = positionWS;
         float3 normalBias = EvalShadow_NormalBias(sd.worldTexelSize, sd.normalBias, normalWS);
         positionWS += normalBias;
-
+    #endif
         /* get shadowmap texcoords */
         float3 posTC = EvalShadow_GetTexcoordsAtlas(sd, _CascadeShadowAtlasSize.zw, positionWS, false);
         /* evalute the first cascade */
@@ -278,11 +284,10 @@ float EvalShadow_CascadedDepth_Dither(HDShadowContext shadowContext, Texture2D t
         HDShadowData sd = shadowContext.shadowDatas[index];
         LoadDirectionalShadowDatas(sd, shadowContext, index + shadowSplitIndex);
         positionWS = positionWS + sd.cacheTranslationDelta.xyz;
-
+    #if SHADOW_USE_NORMAL_BIAS
         /* normal based bias */
         float worldTexelSize = sd.worldTexelSize;
         float3 normalBias = EvalShadow_NormalBias(worldTexelSize, sd.normalBias, normalWS);
-
         /* We select what split we need to sample from */
         float nextSplit = min(shadowSplitIndex + 1, cascadeCount - 1);
         bool evalNextCascade = nextSplit != shadowSplitIndex && step(InterleavedGradientNoise(positionSS.xy, _TaaFrameInfo.z), alpha);
@@ -295,6 +300,7 @@ float EvalShadow_CascadedDepth_Dither(HDShadowContext shadowContext, Texture2D t
         }
 
         positionWS += normalBias;
+    #endif
         float3 posTC = EvalShadow_GetTexcoordsAtlas(sd, _CascadeShadowAtlasSize.zw, positionWS, false);
 
         shadow = DIRECTIONAL_FILTER_ALGORITHM(sd, positionSS, posTC, tex, samp, FIXED_UNIFORM_BIAS);

diff --git a/...-pipelines.high-definition/Runtime/Lighting/VolumetricLighting/VolumetricLighting.compute b/...-pipelines.high-definition/Runtime/Lighting/VolumetricLighting/VolumetricLighting.compute
@@ -28,10 +28,12 @@
     #define VBUFFER_VOXEL_SIZE 8
 #endif
 
-#define GROUP_SIZE_1D         8
-#define SUPPORT_LOCAL_LIGHTS  1 // Local lights contribute to fog lighting
-#define SHADOW_USE_DEPTH_BIAS 0
-#define PREFER_HALF           0
+#define PREFER_HALF            0
+#define GROUP_SIZE_1D          8
+#define SUPPORT_LOCAL_LIGHTS   1 // Local lights contribute to fog lighting
+#define SHADOW_USE_DEPTH_BIAS  0 // Too expensive
+#define SHADOW_USE_NORMAL_BIAS 0 // There may be no geometry along the ray, and even if there is geometry along the ray,
+                                 // it only occupies certain slices, and may not have a normal G-buffer to sample.
 
 //--------------------------------------------------------------------------------------------------
 // Included headers