[2022.1] Add Shadow and Additional light variant stripping

com.unity.render-pipelines.universal/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Added public api and updated docs for Light2D shape properties.
 - Added Depth Texture setting for Overlay Camera.
 - Added Depth Priming support for Vulkan with MSAA.
+- Added Shadows and Additional Lights off variants stripping.
 
 ### Changed
 
@@ -31,6 +32,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
 - Removed experimental tile deferred code.
 - VFX: New shadergraph support directly on Universal target.
+- Main light shadow, additional light shadow and additional light keywords are now enabled based on urp setting instead of existence in scene. This allows better variant stripping.
 
 ### Fixed
 - Added warning for lit shader detailed abledo, if texture is not linear. [1342011](https://issuetracker.unity3d.com/issues/detail-maps-packed-differently-in-built-in-vs-urp)

com.unity.render-pipelines.universal/Editor/ShaderPreprocessor.cs

@@ -48,6 +48,8 @@ enum ShaderFeatures
         MainLightShadowsCascade = (1 << 26),
         DrawProcedural = (1 << 27),
         ScreenSpaceOcclusionAfterOpaque = (1 << 28),
+        AdditionalLightsKeepOffVariants = (1 << 29),
+        ShadowsKeepOffVariants = (1 << 30),
     }
 
     [Flags]
@@ -358,12 +360,22 @@ bool StripUnusedFeatures(ShaderFeatures features, Shader shader, ShaderSnippetDa
             var stripTool = new StripTool<ShaderFeatures>(features, shader, snippetData, compilerData.shaderKeywordSet, stripUnusedVariants);
 
             // strip main light shadows, cascade and screen variants
-            // TODO: Strip disabled keyword once no light will re-use same variant
-            if (stripTool.StripMultiCompileKeepOffVariant(
-                m_MainLightShadows, ShaderFeatures.MainLightShadows,
-                m_MainLightShadowsCascades, ShaderFeatures.MainLightShadowsCascade,
-                m_MainLightShadowsScreen, ShaderFeatures.ScreenSpaceShadows))
-                return true;
+            if (IsFeatureEnabled(ShaderFeatures.ShadowsKeepOffVariants, features))
+            {
+                if (stripTool.StripMultiCompileKeepOffVariant(
+                    m_MainLightShadows, ShaderFeatures.MainLightShadows,
+                    m_MainLightShadowsCascades, ShaderFeatures.MainLightShadowsCascade,
+                    m_MainLightShadowsScreen, ShaderFeatures.ScreenSpaceShadows))
+                    return true;
+            }
+            else
+            {
+                if (stripTool.StripMultiCompile(
+                    m_MainLightShadows, ShaderFeatures.MainLightShadows,
+                    m_MainLightShadowsCascades, ShaderFeatures.MainLightShadowsCascade,
+                    m_MainLightShadowsScreen, ShaderFeatures.ScreenSpaceShadows))
+                    return true;
+            }
 
             // TODO: Strip off variants once we have global soft shadows option for forcing instead as support
             if (stripTool.StripMultiCompileKeepOffVariant(m_SoftShadows, ShaderFeatures.SoftShadows))
@@ -400,9 +412,16 @@ bool StripUnusedFeatures(ShaderFeatures features, Shader shader, ShaderSnippetDa
                 return true;
 
             // No additional light shadows
-            // TODO: Strip off variants once we support no shadow lights re-use same variant
-            if (stripTool.StripMultiCompileKeepOffVariant(m_AdditionalLightShadows, ShaderFeatures.AdditionalLightShadows))
-                return true;
+            if (IsFeatureEnabled(ShaderFeatures.ShadowsKeepOffVariants, features))
+            {
+                if (stripTool.StripMultiCompileKeepOffVariant(m_AdditionalLightShadows, ShaderFeatures.AdditionalLightShadows))
+                    return true;
+            }
+            else
+            {
+                if (stripTool.StripMultiCompile(m_AdditionalLightShadows, ShaderFeatures.AdditionalLightShadows))
+                    return true;
+            }
 
             if (stripTool.StripMultiCompile(m_ReflectionProbeBlending, ShaderFeatures.ReflectionProbeBlending))
                 return true;
@@ -425,10 +444,18 @@ bool StripUnusedFeatures(ShaderFeatures features, Shader shader, ShaderSnippetDa
             }
 
             // Additional light are shaded per-vertex or per-pixel.
-            // TODO: Strip off variants once we support no additional lights re-used variants
-            if (stripTool.StripMultiCompileKeepOffVariant(m_AdditionalLightsVertex, ShaderFeatures.VertexLighting,
-                m_AdditionalLightsPixel, ShaderFeatures.AdditionalLights))
-                return true;
+            if (IsFeatureEnabled(ShaderFeatures.AdditionalLightsKeepOffVariants, features))
+            {
+                if (stripTool.StripMultiCompileKeepOffVariant(m_AdditionalLightsVertex, ShaderFeatures.VertexLighting,
+                    m_AdditionalLightsPixel, ShaderFeatures.AdditionalLights))
+                    return true;
+            }
+            else
+            {
+                if (stripTool.StripMultiCompile(m_AdditionalLightsVertex, ShaderFeatures.VertexLighting,
+                    m_AdditionalLightsPixel, ShaderFeatures.AdditionalLights))
+                    return true;
+            }
 
             if (stripTool.StripMultiCompile(m_ClusteredRendering, ShaderFeatures.ClusteredRendering))
                 return true;
@@ -921,6 +948,12 @@ private static ShaderFeatures GetSupportedShaderFeatures(UniversalRenderPipeline
                     }
                 }
 
+                if (!renderer.stripShadowsOffVariants)
+                    shaderFeatures |= ShaderFeatures.ShadowsKeepOffVariants;
+
+                if (!renderer.stripAdditionalLightOffVariants)
+                    shaderFeatures |= ShaderFeatures.AdditionalLightsKeepOffVariants;
+
                 var rendererClustered = false;
 
                 ScriptableRendererData rendererData = pipelineAsset.m_RendererDataList[rendererIndex];

com.unity.render-pipelines.universal/Runtime/ForwardLights.cs

@@ -353,10 +353,11 @@ public void Setup(ScriptableRenderContext context, ref RenderingData renderingDa
 
                 SetupShaderLightConstants(cmd, ref renderingData);
 
+                bool lightCountCheck = (renderingData.cameraData.renderer.stripAdditionalLightOffVariants && renderingData.lightData.supportsAdditionalLights) || additionalLightsCount > 0;
                 CoreUtils.SetKeyword(cmd, ShaderKeywordStrings.AdditionalLightsVertex,
-                    additionalLightsCount > 0 && additionalLightsPerVertex && !useClusteredRendering);
+                    lightCountCheck && additionalLightsPerVertex && !useClusteredRendering);
                 CoreUtils.SetKeyword(cmd, ShaderKeywordStrings.AdditionalLightsPixel,
-                    additionalLightsCount > 0 && !additionalLightsPerVertex && !useClusteredRendering);
+                    lightCountCheck && !additionalLightsPerVertex && !useClusteredRendering);
                 CoreUtils.SetKeyword(cmd, ShaderKeywordStrings.ClusteredRendering,
                     useClusteredRendering);
 

com.unity.render-pipelines.universal/Runtime/Passes/AdditionalLightsShadowCasterPass.cs

@@ -48,6 +48,12 @@ public ShadowResolutionRequest(int _visibleLightIndex, int _perLightShadowSliceI
             }
         }
 
+        /// <summary>
+        /// x is used in RenderAdditionalShadowMapAtlas to skip shadow map rendering for non-shadow-casting lights.
+        /// w is perLightFirstShadowSliceIndex, used in Lighting shader to find if Additional light casts shadows.
+        /// </summary>
+        readonly static Vector4 c_DefaultShadowParams = new Vector4(0, 0, 0, -1);
+
         static int m_AdditionalLightsWorldToShadow_SSBO;
         static int m_AdditionalShadowParams_SSBO;
         bool m_UseStructuredBuffer;
@@ -76,6 +82,8 @@ public ShadowResolutionRequest(int _visibleLightIndex, int _perLightShadowSliceI
         int[] m_VisibleLightIndexToSortedShadowResolutionRequestsFirstSliceIndex = null;                 // for each visible light, store the index of its first shadow slice in m_SortedShadowResolutionRequests (for quicker access)
         List<RectInt> m_UnusedAtlasSquareAreas = new List<RectInt>();                                    // this list tracks space available in the atlas
 
+        bool m_CreateEmptyShadowmap;
+
         bool m_SupportsBoxFilterForShadows;
         ProfilingSampler m_ProfilingSetupSampler = new ProfilingSampler("Setup Additional Shadows");
 
@@ -608,11 +616,8 @@ public bool Setup(ref RenderingData renderingData)
                 m_AdditionalLightShadowSliceIndexTo_WorldShadowMatrix = new Matrix4x4[totalShadowSlicesCount];
 
             // initialize _AdditionalShadowParams
-            Vector4 defaultShadowParams = new Vector4(0 /*shadowStrength*/, 0, 0, -1 /*perLightFirstShadowSliceIndex*/);
-            // shadowParams.x is used in RenderAdditionalShadowMapAtlas to skip shadow map rendering for non-shadow-casting lights
-            // shadowParams.w is used in Lighting shader to find if Additional light casts shadows
             for (int i = 0; i < maxAdditionalLightShadowParams; ++i)
-                m_AdditionalLightIndexToShadowParams[i] = defaultShadowParams;
+                m_AdditionalLightIndexToShadowParams[i] = c_DefaultShadowParams;
 
             int validShadowCastingLightsCount = 0;
             bool supportsSoftShadows = renderingData.shadowData.supportsSoftShadows;
@@ -731,7 +736,7 @@ public bool Setup(ref RenderingData renderingData)
 
             // Lights that need to be rendered in the shadow map atlas
             if (validShadowCastingLightsCount == 0)
-                return false;
+                return SetupForEmptyRendering(ref renderingData);
 
             int shadowCastingLightsBufferCount = m_ShadowSliceToAdditionalLightIndex.Count;
 
@@ -786,6 +791,24 @@ public bool Setup(ref RenderingData renderingData)
             m_AdditionalLightsShadowmapTexture = ShadowUtils.GetTemporaryShadowTexture(renderTargetWidth, renderTargetHeight, k_ShadowmapBufferBits);
             m_MaxShadowDistanceSq = renderingData.cameraData.maxShadowDistance * renderingData.cameraData.maxShadowDistance;
             m_CascadeBorder = renderingData.shadowData.mainLightShadowCascadeBorder;
+            m_CreateEmptyShadowmap = false;
+            useNativeRenderPass = true;
+
+            return true;
+        }
+
+        bool SetupForEmptyRendering(ref RenderingData renderingData)
+        {
+            if (!renderingData.cameraData.renderer.stripShadowsOffVariants)
+                return false;
+
+            m_AdditionalLightsShadowmapTexture = ShadowUtils.GetTemporaryShadowTexture(1, 1, k_ShadowmapBufferBits);
+            m_CreateEmptyShadowmap = true;
+            useNativeRenderPass = false;
+
+            // initialize _AdditionalShadowParams
+            for (int i = 0; i < m_AdditionalLightIndexToShadowParams.Length; ++i)
+                m_AdditionalLightIndexToShadowParams[i] = c_DefaultShadowParams;
 
             return true;
         }
@@ -799,6 +822,12 @@ public override void Configure(CommandBuffer cmd, RenderTextureDescriptor camera
         /// <inheritdoc/>
         public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
         {
+            if (m_CreateEmptyShadowmap)
+            {
+                SetEmptyAdditionalShadowmapAtlas(ref context);
+                return;
+            }
+
             if (renderingData.shadowData.supportsAdditionalLightShadows)
                 RenderAdditionalShadowmapAtlas(ref context, ref renderingData.cullResults, ref renderingData.lightData, ref renderingData.shadowData);
         }
@@ -832,6 +861,24 @@ void Clear()
             m_AdditionalLightsShadowmapTexture = null;
         }
 
+        void SetEmptyAdditionalShadowmapAtlas(ref ScriptableRenderContext context)
+        {
+            CommandBuffer cmd = CommandBufferPool.Get();
+            CoreUtils.SetKeyword(cmd, ShaderKeywordStrings.AdditionalLightShadows, true);
+            if (RenderingUtils.useStructuredBuffer)
+            {
+                var shadowParamsBuffer = ShaderData.instance.GetAdditionalLightShadowParamsStructuredBuffer(m_AdditionalLightIndexToShadowParams.Length);
+                shadowParamsBuffer.SetData(m_AdditionalLightIndexToShadowParams);
+                cmd.SetGlobalBuffer(m_AdditionalShadowParams_SSBO, shadowParamsBuffer);
+            }
+            else
+            {
+                cmd.SetGlobalVectorArray(AdditionalShadowsConstantBuffer._AdditionalShadowParams, m_AdditionalLightIndexToShadowParams);
+            }
+            context.ExecuteCommandBuffer(cmd);
+            CommandBufferPool.Release(cmd);
+        }
+
         void RenderAdditionalShadowmapAtlas(ref ScriptableRenderContext context, ref CullingResults cullResults, ref LightData lightData, ref ShadowData shadowData)
         {
             NativeArray<VisibleLight> visibleLights = lightData.visibleLights;

com.unity.render-pipelines.universal/Runtime/Passes/MainLightShadowCasterPass.cs

@@ -38,6 +38,8 @@ private static class MainLightShadowConstantBuffer
         ShadowSliceData[] m_CascadeSlices;
         Vector4[] m_CascadeSplitDistances;
 
+        bool m_CreateEmptyShadowmap;
+
         ProfilingSampler m_ProfilingSetupSampler = new ProfilingSampler("Setup Main Shadowmap");
 
         public MainLightShadowCasterPass(RenderPassEvent evt)
@@ -71,17 +73,17 @@ public bool Setup(ref RenderingData renderingData)
             using var profScope = new ProfilingScope(null, m_ProfilingSetupSampler);
 
             if (!renderingData.shadowData.supportsMainLightShadows)
-                return false;
+                return SetupForEmptyRendering(ref renderingData);
 
             Clear();
             int shadowLightIndex = renderingData.lightData.mainLightIndex;
             if (shadowLightIndex == -1)
-                return false;
+                return SetupForEmptyRendering(ref renderingData);
 
             VisibleLight shadowLight = renderingData.lightData.visibleLights[shadowLightIndex];
             Light light = shadowLight.light;
             if (light.shadows == LightShadows.None)
-                return false;
+                return SetupForEmptyRendering(ref renderingData);
 
             if (shadowLight.lightType != LightType.Directional)
             {
@@ -90,7 +92,7 @@ public bool Setup(ref RenderingData renderingData)
 
             Bounds bounds;
             if (!renderingData.cullResults.GetShadowCasterBounds(shadowLightIndex, out bounds))
-                return false;
+                return SetupForEmptyRendering(ref renderingData);
 
             m_ShadowCasterCascadesCount = renderingData.shadowData.mainLightShadowCascadesCount;
 
@@ -108,12 +110,26 @@ public bool Setup(ref RenderingData renderingData)
                     out m_CascadeSplitDistances[cascadeIndex], out m_CascadeSlices[cascadeIndex]);
 
                 if (!success)
-                    return false;
+                    return SetupForEmptyRendering(ref renderingData);
             }
 
             m_MainLightShadowmapTexture = ShadowUtils.GetTemporaryShadowTexture(renderTargetWidth, renderTargetHeight, k_ShadowmapBufferBits);
             m_MaxShadowDistanceSq = renderingData.cameraData.maxShadowDistance * renderingData.cameraData.maxShadowDistance;
             m_CascadeBorder = renderingData.shadowData.mainLightShadowCascadeBorder;
+            m_CreateEmptyShadowmap = false;
+            useNativeRenderPass = true;
+
+            return true;
+        }
+
+        bool SetupForEmptyRendering(ref RenderingData renderingData)
+        {
+            if (!renderingData.cameraData.renderer.stripShadowsOffVariants)
+                return false;
+
+            m_MainLightShadowmapTexture = ShadowUtils.GetTemporaryShadowTexture(1, 1, k_ShadowmapBufferBits);
+            m_CreateEmptyShadowmap = true;
+            useNativeRenderPass = false;
 
             return true;
         }
@@ -127,6 +143,12 @@ public override void Configure(CommandBuffer cmd, RenderTextureDescriptor camera
         /// <inheritdoc/>
         public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
         {
+            if (m_CreateEmptyShadowmap)
+            {
+                SetEmptyMainLightCascadeShadowmap(ref context);
+                return;
+            }
+
             RenderMainLightCascadeShadowmap(ref context, ref renderingData.cullResults, ref renderingData.lightData, ref renderingData.shadowData);
         }
 
@@ -157,6 +179,19 @@ void Clear()
                 m_CascadeSlices[i].Clear();
         }
 
+        void SetEmptyMainLightCascadeShadowmap(ref ScriptableRenderContext context)
+        {
+            CommandBuffer cmd = CommandBufferPool.Get();
+            CoreUtils.SetKeyword(cmd, ShaderKeywordStrings.MainLightShadows, true);
+            cmd.SetGlobalTexture(m_MainLightShadowmap.id, m_MainLightShadowmapTexture);
+            cmd.SetGlobalVector(MainLightShadowConstantBuffer._ShadowParams,
+                new Vector4(1, 0, 1, 0));
+            cmd.SetGlobalVector(MainLightShadowConstantBuffer._ShadowmapSize,
+                new Vector4(1f / m_MainLightShadowmapTexture.width, 1f / m_MainLightShadowmapTexture.height, m_MainLightShadowmapTexture.width, m_MainLightShadowmapTexture.height));
+            context.ExecuteCommandBuffer(cmd);
+            CommandBufferPool.Release(cmd);
+        }
+
         void RenderMainLightCascadeShadowmap(ref ScriptableRenderContext context, ref CullingResults cullResults, ref LightData lightData, ref ShadowData shadowData)
         {
             int shadowLightIndex = lightData.mainLightIndex;

com.unity.render-pipelines.universal/Runtime/ScriptableRenderer.cs

@@ -489,6 +489,10 @@ internal static void ConfigureActiveTarget(RenderTargetIdentifier colorAttachmen
 
         internal bool useDepthPriming { get; set; } = false;
 
+        internal bool stripShadowsOffVariants { get; set; } = false;
+
+        internal bool stripAdditionalLightOffVariants { get; set; } = false;
+
         public ScriptableRenderer(ScriptableRendererData data)
         {
             if (Debug.isDebugBuild)

com.unity.render-pipelines.universal/Runtime/UniversalRenderPipeline.cs

@@ -1100,6 +1100,7 @@ static void InitializeLightData(UniversalRenderPipelineAsset settings, NativeArr
                 lightData.maxPerObjectAdditionalLightsCount = 0;
             }
 
+            lightData.supportsAdditionalLights = settings.additionalLightsRenderingMode != LightRenderingMode.Disabled;
             lightData.shadeAdditionalLightsPerVertex = settings.additionalLightsRenderingMode == LightRenderingMode.PerVertex;
             lightData.visibleLights = visibleLights;
             lightData.supportsMixedLighting = settings.supportsMixedLighting;

com.unity.render-pipelines.universal/Runtime/UniversalRenderPipelineCore.cs

@@ -43,6 +43,11 @@ public struct LightData
         public bool reflectionProbeBoxProjection;
         public bool reflectionProbeBlending;
         public bool supportsLightLayers;
+
+        /// <summary>
+        /// True if additional lights enabled.
+        /// </summary>
+        public bool supportsAdditionalLights;
     }
 
     public struct CameraData

com.unity.render-pipelines.universal/Runtime/UniversalRenderer.cs

@@ -158,6 +158,9 @@ public UniversalRenderer(UniversalRendererData data) : base(data)
                 m_LightCookieManager = new LightCookieManager(ref settings);
             }
 
+            this.stripShadowsOffVariants = true;
+            this.stripAdditionalLightOffVariants = true;
+
             ForwardLights.InitParams forwardInitParams;
             forwardInitParams.lightCookieManager = m_LightCookieManager;
             forwardInitParams.clusteredRendering = data.clusteredRendering;
@@ -179,6 +182,7 @@ public UniversalRenderer(UniversalRendererData data) : base(data)
             // we inject the builtin passes in the before events.
             m_MainLightShadowCasterPass = new MainLightShadowCasterPass(RenderPassEvent.BeforeRenderingShadows);
             m_AdditionalLightsShadowCasterPass = new AdditionalLightsShadowCasterPass(RenderPassEvent.BeforeRenderingShadows);
+
 #if ENABLE_VR && ENABLE_XR_MODULE
             m_XROcclusionMeshPass = new XROcclusionMeshPass(RenderPassEvent.BeforeRenderingOpaques);
             // Schedule XR copydepth right after m_FinalBlitPass(AfterRendering + 1)