Fix black screen when TAA is enabled on the 2D renderer.

Correctly handle missing motion vectors for TAA. Fixes black screen on the 2D renderer when TAA is enabled.
Does not implement TAA for 2D.

Author: eh-unity

Packages/com.unity.render-pipelines.universal/Runtime/FrameData/UniversalCameraData.cs

@@ -423,12 +423,13 @@ internal bool IsTemporalAAEnabled()
             UniversalAdditionalCameraData additionalCameraData;
             camera.TryGetComponent(out additionalCameraData);
 
-            return (antialiasing == AntialiasingMode.TemporalAntiAliasing)                                                         // Enabled
-                && (taaPersistentData != null)                                                                                     // Initialized
-                && (cameraTargetDescriptor.msaaSamples == 1)                                                                       // No MSAA
-                && !(additionalCameraData?.renderType == CameraRenderType.Overlay || additionalCameraData?.cameraStack.Count > 0)  // No Camera stack
-                && !camera.allowDynamicResolution                                                                                  // No Dynamic Resolution
-                && postProcessEnabled;                                                                                             // No Postprocessing
+            return (antialiasing == AntialiasingMode.TemporalAntiAliasing)                                                            // Enabled
+                   && postProcessEnabled                                                                                              // Postprocessing Enabled
+                   && (taaPersistentData != null)                                                                                     // Initialized
+                   && (cameraTargetDescriptor.msaaSamples == 1)                                                                       // No MSAA
+                   && !(additionalCameraData?.renderType == CameraRenderType.Overlay || additionalCameraData?.cameraStack.Count > 0)  // No Camera stack
+                   && !camera.allowDynamicResolution                                                                                  // No Dynamic Resolution
+                   && renderer.SupportsMotionVectors();                                                                               // Motion Vectors implemented
         }
 
         /// <summary>

Packages/com.unity.render-pipelines.universal/Runtime/Passes/PostProcessPass.cs

@@ -518,8 +518,9 @@ void Swap(ref ScriptableRenderer r)
             {
                 using (new ProfilingScope(cmd, ProfilingSampler.Get(URPProfileId.TemporalAA)))
                 {
+                    Debug.Assert(m_MotionVectors != null, "MotionVectors are invalid. TAA requires a motion vector texture.");
 
-                    TemporalAA.ExecutePass(cmd, m_Materials.temporalAntialiasing, ref renderingData.cameraData, source, destination, m_MotionVectors.rt);
+                    TemporalAA.ExecutePass(cmd, m_Materials.temporalAntialiasing, ref renderingData.cameraData, source, destination, m_MotionVectors?.rt);
                     Swap(ref renderer);
                 }
             }
@@ -766,8 +767,8 @@ void DoSubpixelMorphologicalAntialiasing(ref CameraData cameraData, CommandBuffe
                 material, 0);
 
             // Pass 2: Blend weights
-            RenderingUtils.Blit(cmd, m_EdgeColorTexture, pixelRect, 
-                m_BlendTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store, 
+            RenderingUtils.Blit(cmd, m_EdgeColorTexture, pixelRect,
+                m_BlendTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store,
                 stencil, RenderBufferLoadAction.Load, RenderBufferStoreAction.DontCare,
                 ClearFlag.Color, Color.clear, material, 1);
 
@@ -1215,6 +1216,7 @@ void DoMotionBlur(CommandBuffer cmd, RTHandle source, RTHandle destination, RTHa
             var mode = m_MotionBlur.mode.value;
             if (mode == MotionBlurMode.CameraAndObjects)
             {
+                Debug.Assert(motionVectors != null, "Motion vectors are invalid. Per-object motion blur requires a motion vector texture.");
                 pass += 3;
                 material.SetTexture(MotionVectorRenderPass.k_MotionVectorTextureName, motionVectors);
             }

Packages/com.unity.render-pipelines.universal/Runtime/Passes/PostProcessPassRenderGraph.cs

@@ -999,6 +999,9 @@ private void RenderTemporalAA(RenderGraph renderGraph, UniversalResourceData res
 
             TextureHandle cameraDepth = resourceData.cameraDepth;
             TextureHandle motionVectors = resourceData.motionVectorColor;
+
+            Debug.Assert(motionVectors.IsValid(), "MotionVectors are invalid. TAA requires a motion vector texture.");
+
             TemporalAA.Render(renderGraph, m_Materials.temporalAntialiasing, cameraData, ref source, ref cameraDepth, ref motionVectors, ref destination);
         }
         #endregion
@@ -1012,6 +1015,8 @@ private void RenderSTP(RenderGraph renderGraph, UniversalResourceData resourceDa
             TextureHandle cameraDepth = resourceData.cameraDepth;
             TextureHandle motionVectors = resourceData.motionVectorColor;
 
+            Debug.Assert(motionVectors.IsValid(), "MotionVectors are invalid. STP requires a motion vector texture.");
+
             var desc = GetCompatibleDescriptor(cameraData.cameraTargetDescriptor,
                 cameraData.pixelWidth,
                 cameraData.pixelHeight,
@@ -1061,13 +1066,13 @@ public void RenderMotionBlur(RenderGraph renderGraph, UniversalResourceData reso
 
             destination = UniversalRenderer.CreateRenderGraphTexture(renderGraph, desc, "_MotionBlurTarget", true, FilterMode.Bilinear);
 
+            TextureHandle motionVectorColor = resourceData.motionVectorColor;
+            TextureHandle cameraDepthTexture = resourceData.cameraDepthTexture;
+
             var mode = m_MotionBlur.mode.value;
             int passIndex = (int)m_MotionBlur.quality.value;
             passIndex += (mode == MotionBlurMode.CameraAndObjects) ? 3 : 0;
 
-            TextureHandle motionVectorColor = resourceData.motionVectorColor;
-            TextureHandle cameraDepthTexture = resourceData.cameraDepthTexture;
-
             using (var builder = renderGraph.AddRasterRenderPass<MotionBlurPassData>("Motion Blur", out var passData, ProfilingSampler.Get(URPProfileId.RG_MotionBlur)))
             {
                 builder.AllowGlobalStateModification(true);
@@ -1078,6 +1083,8 @@ public void RenderMotionBlur(RenderGraph renderGraph, UniversalResourceData reso
 
                 if (mode == MotionBlurMode.CameraAndObjects)
                 {
+                    Debug.Assert(motionVectorColor.IsValid(), "Motion vectors are invalid. Per-object motion blur requires a motion vector texture.");
+
                     passData.motionVectors = motionVectorColor;
                     builder.UseTexture(motionVectorColor, AccessFlags.Read);
                 }

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

@@ -88,6 +88,26 @@ public bool SupportsCameraStackingType(CameraRenderType cameraRenderType)
             return (SupportedCameraStackingTypes() & 1 << (int)cameraRenderType) != 0;
         }
 
+
+        // NOTE: This is a temporary solution until ScriptableRenderer has a system for partially shared features.
+        // TAA (and similar) affect the whole pipe. The code is split into two parts in terms of ownership.
+        // The ScriptableRenderer "shared" code (Camera) and the ScriptableRenderer "specific" code (the ScriptableRenderPasses).
+        // For example: TAA is enabled and configured from the Camera, which is used by any ScriptableRenderer.
+        // TAA also jitters the Camera matrix for all ScriptableRenderers.
+        // However a Renderer might not implement a motion vector pass, which the TAA needs to function correctly.
+        //
+        /// <summary>
+        /// Check if the ScriptableRenderer implements a motion vector pass for temporal techniques.
+        /// The Camera will check this to enable/disable features and/or apply jitter when required.
+        ///
+        /// For example, Temporal Anti-aliasing in the Camera settings is enabled only if the ScriptableRenderer can support motion vectors.
+        /// </summary>
+        /// <returns>Returns true if the ScriptableRenderer implements a motion vector pass. False otherwise.</returns>
+        protected internal virtual bool SupportsMotionVectors()
+        {
+            return false;
+        }
+
         /// <summary>
         /// Override to provide a custom profiling name
         /// </summary>

Packages/com.unity.render-pipelines.universal/Runtime/TemporalAA.cs

@@ -323,6 +323,9 @@ internal static string ValidateAndWarn(UniversalCameraData cameraData)
         {
             string warning = null;
 
+            if(warning == null && !cameraData.postProcessEnabled)
+                warning = "Disabling TAA because camera has post-processing disabled.";
+
             if (cameraData.taaPersistentData == null)
             {
                 warning = "Disabling TAA due to invalid persistent data.";
@@ -348,8 +351,8 @@ internal static string ValidateAndWarn(UniversalCameraData cameraData)
             if (warning == null && cameraData.camera.allowDynamicResolution)
                 warning = "Disabling TAA because camera has dynamic resolution enabled. You can use a constant render scale instead.";
 
-            if(warning == null && !cameraData.postProcessEnabled)
-                warning = "Disabling TAA because camera has post-processing disabled.";
+            if(warning == null && !cameraData.renderer.SupportsMotionVectors())
+                warning = "Disabling TAA because the renderer does not implement motion vectors. Motion vectors are required for TAA.";
 
             const int warningThrottleFrames = 60 * 1; // 60 FPS * 1 sec
             if(Time.frameCount % warningThrottleFrames == 0)

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

@@ -73,6 +73,13 @@ public override int SupportedCameraStackingTypes()
             }
         }
 
+        /// <inheritdoc/>
+        protected internal override bool SupportsMotionVectors()
+        {
+            // Motion vector pass for TAA and per-object motion blur (etc.) is available.
+            return true;
+        }
+
         // Rendering mode setup from UI. The final rendering mode used can be different. See renderingModeActual.
         internal RenderingMode renderingModeRequested => m_RenderingMode;