Merge pull request #689 from Unity-Technologies/Add-support-of-transparent-depth-prepass

Add support of transparent depth prepass

ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.cs

 
         void RenderTransparentDepthPostPass(CullResults cullResults, Camera camera, ScriptableRenderContext renderContext, CommandBuffer cmd, ForwardPass pass)
         {
-            if (m_FrameSettings.renderSettings.enableTransparentPostPass)
+            if (!m_FrameSettings.renderSettings.enableTransparentPostPass)
                 return;
 
             using (new ProfilingSample(cmd, "Render Transparent Depth Post ", GetSampler(CustomSamplerId.TransparentDepthPostPass)))

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.shader

 
         [ToggleOff]  _AlphaCutoffEnable("Alpha Cutoff Enable", Float) = 0.0
         _AlphaCutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
+        _AlphaCutoffPrepass("_AlphaCutoffPrepass", Range(0.0, 1.0)) = 0.5
+        [ToggleOff] _TransparentDepthPrepassEnable("_TransparentDepthPrepassEnable", Float) = 0.0
         [ToggleOff] _TransparentBackfaceEnable("_TransparentBackfaceEnable", Float) = 0.0
         [ToggleOff] _TransparentDepthPostpassEnable("_TransparentDepthPostpassEnable", Float) = 0.0
 
             #include "ShaderPass/LitDistortionPass.hlsl"
             #include "LitData.hlsl"
             #include "../../ShaderPass/ShaderPassDistortion.hlsl"
+
+            ENDHLSL
+        }
+
+        // Caution: Order of pass mater. It should be:
+        // TransparentDepthPrepass, TransparentBackface, Forward/ForwardOnly, TransparentDepthPostpass
+        Pass
+        {
+            Name "TransparentDepthPrepass"
+            Tags{ "LightMode" = "TransparentDepthPrepass" }
+
+            Cull[_CullMode]
+            ZWrite On
+            ColorMask 0
+
+            HLSLPROGRAM
+
+            #define SHADERPASS SHADERPASS_DEPTH_ONLY
+            #define CUTOFF_TRANSPARENT_DEPTH_PREPASS
+            #include "../../ShaderVariables.hlsl"
+            #include "../../Material/Material.hlsl"
+            #include "ShaderPass/LitDepthPass.hlsl"
+            #include "LitData.hlsl"
+            #include "../../ShaderPass/ShaderPassDepthOnly.hlsl"
 
             ENDHLSL
         }

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitDataIndividualLayer.hlsl

     // Perform alha test very early to save performance (a killed pixel will not sample textures)
 #if defined(_ALPHATEST_ON) && !defined(LAYERED_LIT_SHADER)
     float alphaCutoff = _AlphaCutoff;
-    #ifdef CUTOFF_TRANSPARENT_DEPTH_POSTPASS
+    #ifdef CUTOFF_TRANSPARENT_DEPTH_PREPASS
+    alphaCutoff = _AlphaCutoffPrepass;
+    #elif defined(CUTOFF_TRANSPARENT_DEPTH_POSTPASS)
     alphaCutoff = _AlphaCutoffPostpass;
     #endif
     DoAlphaTest(alpha, alphaCutoff);
     surfaceData.baseColor = SAMPLE_UVMAPPING_TEXTURE2D(ADD_IDX(_BaseColorMap), ADD_ZERO_IDX(sampler_BaseColorMap), ADD_IDX(layerTexCoord.base)).rgb * ADD_IDX(_BaseColor).rgb;
 #ifdef _DETAIL_MAP_IDX
     // Use overlay blend mode for detail abledo: (base < 0.5 ? (2.0 * base * blend) : (1.0 - 2.0 * (1.0 - base) * (1.0 - blend)))
-    float3 baseColorOverlay = (detailAlbedo < 0.5) ? 
+    float3 baseColorOverlay = (detailAlbedo < 0.5) ?
                                 surfaceData.baseColor * PositivePow(2.0 * detailAlbedo, ADD_IDX(_DetailAlbedoScale)) :
                                 1.0 - (1.0 - surfaceData.baseColor) * PositivePow(2.0 * (1.0 - detailAlbedo), ADD_IDX(_DetailAlbedoScale));
     // Lerp with details mask
     surfaceData.atDistance = _ATDistance;
     // Thickness already defined with SSS (from both thickness and thicknessMap)
     surfaceData.thickness *= _ThicknessMultiplier;
-    // Rough refraction don't use opacity. Instead we use opacity as a transmittance mask. 
+    // Rough refraction don't use opacity. Instead we use opacity as a transmittance mask.
     surfaceData.transmittanceMask = 1.0 - alpha;
     alpha = 1.0;
 #else

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitProperties.hlsl

 
 // shared constant between lit and layered lit
 float _AlphaCutoff;
+float _AlphaCutoffPrepass;
 float _AlphaCutoffPostpass;
 float4 _DoubleSidedConstants;
 float _DistortionScale;

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/LitTessellation.shader

 
         [ToggleOff]  _AlphaCutoffEnable("Alpha Cutoff Enable", Float) = 0.0
         _AlphaCutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
+        _AlphaCutoffPrepass("_AlphaCutoffPrepass", Range(0.0, 1.0)) = 0.5
+        [ToggleOff] _TransparentDepthPrepassEnable("_TransparentDepthPrepassEnable", Float) = 0.0
         [ToggleOff] _TransparentBackfaceEnable("_TransparentBackfaceEnable", Float) = 0.0
         [ToggleOff] _TransparentDepthPostpassEnable("_TransparentDepthPostpassEnable", Float) = 0.0
 
             ENDHLSL
         }
 
+        // Caution: Order of pass mater. It should be:
+        // TransparentDepthPrepass, TransparentBackface, Forward/ForwardOnly, TransparentDepthPostpass
+        Pass
+        {
+            Name "TransparentDepthPrepass"
+            Tags{ "LightMode" = "TransparentDepthPrepass" }
+
+            Cull[_CullMode]
+            ZWrite On
+            ColorMask 0
+
+            HLSLPROGRAM
+
+            #pragma hull Hull
+            #pragma domain Domain
+
+            #define SHADERPASS SHADERPASS_DEPTH_ONLY
+            #define CUTOFF_TRANSPARENT_DEPTH_PREPASS
+            #include "../../ShaderVariables.hlsl"
+            #include "../../Material/Material.hlsl"
+            #include "ShaderPass/LitDepthPass.hlsl"
+            #include "LitData.hlsl"
+            #include "../../ShaderPass/ShaderPassDepthOnly.hlsl"
+
+            ENDHLSL
+        }
+
         Pass
         {
             Name "TransparentBackface"
             ColorMask 0
 
             HLSLPROGRAM
+
+            #pragma hull Hull
+            #pragma domain Domain
 
             #define SHADERPASS SHADERPASS_DEPTH_ONLY
             #define CUTOFF_TRANSPARENT_DEPTH_POSTPASS