URP: Fixes for the new Unity 6 RenderPass

- Properly composite with other 3D objects in the scene (use depth),
- Properly declare inputs/outputs
- Actually stop using deprecated APIs

Author: aras-p

package/Runtime/GaussianSplatURPFeature.cs

@@ -5,7 +5,7 @@
 using UnityEngine.Experimental.Rendering;
 using UnityEngine.Rendering;
 using UnityEngine.Rendering.Universal;
-#if UNITY_6000
+#if UNITY_6000_0_OR_NEWER
 using UnityEngine.Rendering.RenderGraphModule;
 #endif
 
@@ -21,58 +21,35 @@ class GaussianSplatURPFeature : ScriptableRendererFeature
         class GSRenderPass : ScriptableRenderPass
         {
             const string GaussianSplatRTName = "_GaussianSplatRT";
+#if !UNITY_6000_0_OR_NEWER
             RTHandle m_RenderTarget;
-            internal ScriptableRenderer m_Renderer = null;
-            internal CommandBuffer m_Cmb = null;
+            internal ScriptableRenderer m_Renderer;
+            internal CommandBuffer m_Cmb;
+#endif
 
             public void Dispose()
             {
+#if !UNITY_6000_0_OR_NEWER
                 m_RenderTarget?.Release();
+#endif
             }
 
-            public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
-            {
-                RenderTextureDescriptor rtDesc = renderingData.cameraData.cameraTargetDescriptor;
-                rtDesc.depthBufferBits = 0;
-                rtDesc.msaaSamples = 1;
-                rtDesc.graphicsFormat = GraphicsFormat.R16G16B16A16_SFloat;
-                RenderingUtils.ReAllocateIfNeeded(ref m_RenderTarget, rtDesc, FilterMode.Point, TextureWrapMode.Clamp, name: GaussianSplatRTName);
-                cmd.SetGlobalTexture(m_RenderTarget.name, m_RenderTarget.nameID);
-
-                ConfigureTarget(m_RenderTarget, m_Renderer.cameraDepthTargetHandle);
-                ConfigureClear(ClearFlag.Color, new Color(0,0,0,0));
-            }
-
-            public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
-            {
-                if (m_Cmb == null)
-                    return;
-
-                // add sorting, view calc and drawing commands for each splat object
-                Material matComposite = GaussianSplatRenderSystem.instance.SortAndRenderSplats(renderingData.cameraData.camera, m_Cmb);
-
-                // compose
-                m_Cmb.BeginSample(GaussianSplatRenderSystem.s_ProfCompose);
-                Blitter.BlitCameraTexture(m_Cmb, m_RenderTarget, m_Renderer.cameraColorTargetHandle, RenderBufferLoadAction.Load, RenderBufferStoreAction.Store, matComposite, 0);
-                m_Cmb.EndSample(GaussianSplatRenderSystem.s_ProfCompose);
-                context.ExecuteCommandBuffer(m_Cmb);
-            }
-
-#if UNITY_6000
-            private const string ProfilerTag = "GaussianSplatRenderGraph";
-            private static readonly ProfilingSampler s_profilingSampler = new(ProfilerTag);
-            private static readonly int s_gaussianSplatRT = Shader.PropertyToID(GaussianSplatRTName);
+#if UNITY_6000_0_OR_NEWER
+            const string ProfilerTag = "GaussianSplatRenderGraph";
+            static readonly ProfilingSampler s_profilingSampler = new(ProfilerTag);
+            static readonly int s_gaussianSplatRT = Shader.PropertyToID(GaussianSplatRTName);
 
-            private class PassData
+            class PassData
             {
                 internal UniversalCameraData CameraData;
                 internal TextureHandle SourceTexture;
+                internal TextureHandle SourceDepth;
                 internal TextureHandle GaussianSplatRT;
             }
 
             public override void RecordRenderGraph(RenderGraph renderGraph, ContextContainer frameData)
             {
-                using var builder = renderGraph.AddUnsafePass<PassData>(ProfilerTag, out PassData passData);
+                using var builder = renderGraph.AddUnsafePass(ProfilerTag, out PassData passData);
 
                 var cameraData = frameData.Get<UniversalCameraData>();
                 var resourceData = frameData.Get<UniversalResourceData>();
@@ -85,22 +62,53 @@ public override void RecordRenderGraph(RenderGraph renderGraph, ContextContainer
 
                 passData.CameraData = cameraData;
                 passData.SourceTexture = resourceData.activeColorTexture;
+                passData.SourceDepth = resourceData.activeDepthTexture;
                 passData.GaussianSplatRT = textureHandle;
 
+                builder.UseTexture(resourceData.activeColorTexture, AccessFlags.ReadWrite);
+                builder.UseTexture(resourceData.activeDepthTexture);
                 builder.UseTexture(textureHandle, AccessFlags.Write);
                 builder.AllowPassCulling(false);
                 builder.SetRenderFunc(static (PassData data, UnsafeGraphContext context) =>
                 {
                     var commandBuffer = CommandBufferHelpers.GetNativeCommandBuffer(context.cmd);
                     using var _ = new ProfilingScope(commandBuffer, s_profilingSampler);
                     commandBuffer.SetGlobalTexture(s_gaussianSplatRT, data.GaussianSplatRT);
-                    CoreUtils.SetRenderTarget(commandBuffer, data.GaussianSplatRT, ClearFlag.Color, Color.clear);
+                    CoreUtils.SetRenderTarget(commandBuffer, data.GaussianSplatRT, data.SourceDepth, ClearFlag.Color, Color.clear);
                     Material matComposite = GaussianSplatRenderSystem.instance.SortAndRenderSplats(data.CameraData.camera, commandBuffer);
                     commandBuffer.BeginSample(GaussianSplatRenderSystem.s_ProfCompose);
                     Blitter.BlitCameraTexture(commandBuffer, data.GaussianSplatRT, data.SourceTexture, matComposite, 0);
                     commandBuffer.EndSample(GaussianSplatRenderSystem.s_ProfCompose);
                 });
             }
+#else
+            public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
+            {
+                RenderTextureDescriptor rtDesc = renderingData.cameraData.cameraTargetDescriptor;
+                rtDesc.depthBufferBits = 0;
+                rtDesc.msaaSamples = 1;
+                rtDesc.graphicsFormat = GraphicsFormat.R16G16B16A16_SFloat;
+                RenderingUtils.ReAllocateIfNeeded(ref m_RenderTarget, rtDesc, FilterMode.Point, TextureWrapMode.Clamp, name: GaussianSplatRTName);
+                cmd.SetGlobalTexture(m_RenderTarget.name, m_RenderTarget.nameID);
+
+                ConfigureTarget(m_RenderTarget, m_Renderer.cameraDepthTargetHandle);
+                ConfigureClear(ClearFlag.Color, new Color(0,0,0,0));
+            }
+
+            public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
+            {
+                if (m_Cmb == null)
+                    return;
+
+                // add sorting, view calc and drawing commands for each splat object
+                Material matComposite = GaussianSplatRenderSystem.instance.SortAndRenderSplats(renderingData.cameraData.camera, m_Cmb);
+
+                // compose
+                m_Cmb.BeginSample(GaussianSplatRenderSystem.s_ProfCompose);
+                Blitter.BlitCameraTexture(m_Cmb, m_RenderTarget, m_Renderer.cameraColorTargetHandle, RenderBufferLoadAction.Load, RenderBufferStoreAction.Store, matComposite, 0);
+                m_Cmb.EndSample(GaussianSplatRenderSystem.s_ProfCompose);
+                context.ExecuteCommandBuffer(m_Cmb);
+            }
 #endif
         }
 
@@ -122,16 +130,20 @@ public override void OnCameraPreCull(ScriptableRenderer renderer, in CameraData
             if (!system.GatherSplatsForCamera(cameraData.camera))
                 return;
 
+#if !UNITY_6000_0_OR_NEWER
             CommandBuffer cmb = system.InitialClearCmdBuffer(cameraData.camera);
             m_Pass.m_Cmb = cmb;
+#endif
             m_HasCamera = true;
         }
 
         public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
         {
             if (!m_HasCamera)
                 return;
+#if !UNITY_6000_0_OR_NEWER
             m_Pass.m_Renderer = renderer;
+#endif
             renderer.EnqueuePass(m_Pass);
         }