Fix slope scale depth bias when depth offset is ON

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -378,6 +378,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed case where the SceneView don't refresh when using LightExplorer with a running and Paused game (1354129)
 - Fixed wrong ordering in FrameSettings (Normalize Reflection Probes)
 - Fixed a null ref exception when no opaque objects are rendered.
+- Fixed issue with depth slope scale depth bias when a material uses depth offset.
 
 ### Changed
 - Changed Window/Render Pipeline/HD Render Pipeline Wizard to Window/Rendering/HDRP Wizard

com.unity.render-pipelines.high-definition/Runtime/Lighting/Shadow/HDShadowAtlas.cs

@@ -313,6 +313,7 @@ TextureHandle RenderShadowMaps(RenderGraph renderGraph, CullingResults cullResul
                             data.globalCBData._InvProjMatrix = shadowRequest.deviceProjectionYFlip.inverse;
                             data.globalCBData._ViewProjMatrix = viewProjection;
                             data.globalCBData._InvViewProjMatrix = viewProjection.inverse;
+                            data.globalCBData._SlopeScaleDepthBias = -shadowRequest.slopeBias;
 
                             data.globalCB.PushGlobal(ctx.cmd, data.globalCBData, HDShaderIDs._ShaderVariablesGlobal);
 

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassDepthOnly.hlsl

@@ -96,6 +96,15 @@ void Frag(  PackedVaryingsToPS packedInput
 
 #if defined(_DEPTHOFFSET_ON) && !defined(SCENEPICKINGPASS)
     outputDepth = posInput.deviceDepth;
+
+
+#if SHADERPASS == SHADERPASS_SHADOWS
+    // If we are using the depth offset and manually outputting depth, the slope-scale depth bias is not properly applied
+    // we need to manually apply.
+    float bias = max(abs(ddx(posInput.deviceDepth)), abs(ddy(posInput.deviceDepth))) * _SlopeScaleDepthBias;
+    outputDepth += bias;
+#endif
+
 #endif
 
 #ifdef SCENESELECTIONPASS

com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariablesGlobal.cs

@@ -198,7 +198,7 @@ unsafe struct ShaderVariablesGlobal
         public float _MicroShadowOpacity;
         public uint _EnableProbeVolumes;
         public uint _ProbeVolumeCount;
-        public float _Pad6;
+        public float _SlopeScaleDepthBias;
 
         public Vector4 _CookieAtlasSize;
         public Vector4 _CookieAtlasData;

com.unity.render-pipelines.high-definition/Runtime/ShaderLibrary/ShaderVariablesGlobal.cs.hlsl

@@ -109,7 +109,7 @@ GLOBAL_CBUFFER_START(ShaderVariablesGlobal, b0)
     float _MicroShadowOpacity;
     uint _EnableProbeVolumes;
     uint _ProbeVolumeCount;
-    float _Pad6;
+    float _SlopeScaleDepthBias;
     float4 _CookieAtlasSize;
     float4 _CookieAtlasData;
     float4 _PlanarAtlasData;