Merge pull request #1891 from Unity-Technologies/lw/no_front_to_back_sorting_of_opaques_on_gpu_with_hsr

Disable front-to-back sorting of opaque objects on hardware with HSR

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

 - When __HDR__ is enabled in the Camera but disabled in the Asset, an information box in the Camera Inspector informs you about it.
 - When __MSAA__ is enabled in the Camera but disabled in the Asset, an information box in the Camera Inspector informs you about it.
 - Enabled instancing on the terrain shader.
+- Sorting of opaque objects now respects camera opaqueSortMode setting.
+- Sorting of opaque objects disables front-to-back sorting flag when camera settings allow that and the GPU has hidden surface removal.
+
 ### Fixed
 - The Unlit shader now samples Global Illumination correctly.
 - The Inspector window for the Unlit shader now displays correctly.

com.unity.render-pipelines.lightweight/LWRP/LightweightPipeline.cs

 #endif
 using UnityEngine.Rendering;
 using UnityEngine.Rendering.PostProcessing;
+using UnityEditor.Experimental.Rendering;
+using UnityEngine;
 using UnityEngine.Experimental.GlobalIllumination;
 using Lightmapping = UnityEngine.Experimental.GlobalIllumination.Lightmapping;
 
             }
 
             cameraData.requiresDepthTexture |= cameraData.postProcessEnabled;
+
+            var commonOpaqueFlags = SortFlags.CommonOpaque;
+            var noFrontToBackOpaqueFlags = SortFlags.SortingLayer | SortFlags.RenderQueue | SortFlags.OptimizeStateChanges | SortFlags.CanvasOrder;
+            bool hasHSRGPU = SystemInfo.hasHiddenSurfaceRemovalOnGPU;
+            bool canSkipFrontToBackSorting = (camera.opaqueSortMode == OpaqueSortMode.Default && hasHSRGPU) || camera.opaqueSortMode == OpaqueSortMode.NoDistanceSort;
+
+            cameraData.defaultOpaqueSortFlags = canSkipFrontToBackSorting ? noFrontToBackOpaqueFlags : commonOpaqueFlags;
         }
 
         static void InitializeRenderingData(PipelineSettings settings, ref CameraData cameraData, ref CullResults cullResults,

com.unity.render-pipelines.lightweight/LWRP/LightweightPipelineCore.cs

 using System.Collections.Generic;
 using UnityEngine.Rendering;
 using UnityEngine.Rendering.PostProcessing;
+using UnityEngine.XR;
+using UnityEngine.Experimental.Rendering;
 
 namespace UnityEngine.Experimental.Rendering.LightweightPipeline
 {
         public bool requiresSoftParticles;
         public bool requiresOpaqueTexture;
         public Downsampling opaqueTextureDownsampling;
+
+        public SortFlags defaultOpaqueSortFlags;
 
         public bool isStereoEnabled;
 

com.unity.render-pipelines.lightweight/LWRP/Passes/DepthOnlyPass.cs

                 context.ExecuteCommandBuffer(cmd);
                 cmd.Clear();
 
-                var drawSettings = CreateDrawRendererSettings(renderingData.cameraData.camera, SortFlags.CommonOpaque, RendererConfiguration.None, renderingData.supportsDynamicBatching);
+                var sortFlags = renderingData.cameraData.defaultOpaqueSortFlags;
+                var drawSettings = CreateDrawRendererSettings(renderingData.cameraData.camera, sortFlags, RendererConfiguration.None, renderingData.supportsDynamicBatching);
                 if (renderingData.cameraData.isStereoEnabled)
                 {
                     Camera camera = renderingData.cameraData.camera;

com.unity.render-pipelines.lightweight/LWRP/Passes/RenderOpaqueForwardPass.cs

                 cmd.Clear();
 
                 Camera camera = renderingData.cameraData.camera;
-                var drawSettings = CreateDrawRendererSettings(camera, SortFlags.CommonOpaque, rendererConfiguration, renderingData.supportsDynamicBatching);
+                var sortFlags = renderingData.cameraData.defaultOpaqueSortFlags;
+                var drawSettings = CreateDrawRendererSettings(camera, sortFlags, rendererConfiguration, renderingData.supportsDynamicBatching);
                 context.DrawRenderers(renderingData.cullResults.visibleRenderers, ref drawSettings, m_OpaqueFilterSettings);
 
                 // Render objects that did not match any shader pass with error shader

com.unity.render-pipelines.lightweight/package.json

         "com.unity.render-pipelines.core": "3.4.0-preview",
         "com.unity.shadergraph": "3.4.0-preview"
     }
-}
+}