Merge pull request #1239 from Unity-Technologies/decals/better_atlas_allocation

Only store decal textures to atlas if decal is visible, debounce out …

ScriptableRenderPipeline/HDRenderPipeline/CHANGELOG.md

 - Improve the quality of volumetric lighting reprojection.
 - Optimize Morton Order code in the Subsurface Scattering pass.
 - Planar Reflection Probe support roughness (gaussian convolution of captured probe)
+- Only store decal textures to atlas if decal is visible, debounce out of memory decal atlas warning.
 
 ### Features
 - Screen Space Refraction projection model (Proxy raycasting, HiZ raymarching)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Decal/DecalSystem.cs

 
         private Texture2DAtlas m_Atlas = null;
         public bool m_AllocationSuccess = true;
+        public bool m_PrevAllocationSuccess = true;
 
         public Texture2DAtlas Atlas
         {
             {
                 if (m_NumResults == 0)
                     return;
-
+                // only add if anything in this decal set is visible.
+                AddToTextureList(ref instance.m_TextureList);
                 int instanceCount = 0;
                 int batchCount = 0;
                 Matrix4x4[] decalToWorldBatch = null;
         // updates textures, texture atlas indices and blend value
         public void UpdateCachedMaterialData()
         {
-            //instance.m_AllocationSuccess = true;
-                pair.Value.InitializeMaterialValues();
-                pair.Value.AddToTextureList(ref m_TextureList);
+                pair.Value.InitializeMaterialValues();                
             }
         }
 
                     AddTexture(cmd, textureScaleBias);
                 }
 
-                if(!m_AllocationSuccess) // still failed to allocate, decal atlas size needs to increase
+                if(!m_AllocationSuccess && m_PrevAllocationSuccess) // still failed to allocate, decal atlas size needs to increase, debounce so that we don't spam the console with warnings
+            m_PrevAllocationSuccess = m_AllocationSuccess;
         }
 
         public void CreateDrawData()

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

                             DecalSystem.instance.EndCull();
                             m_DbufferManager.vsibleDecalCount = DecalSystem.m_DecalsVisibleThisFrame;
                             DecalSystem.instance.UpdateCachedMaterialData();    // textures, alpha or fade distances could've changed
-                            DecalSystem.instance.UpdateTextureAtlas(cmd);       // as this is only used for transparent pass, would've been nice not to have to do this if no transparent renderers are visible
+                            DecalSystem.instance.UpdateTextureAtlas(cmd);       // as this is only used for transparent pass, would've been nice not to have to do this if no transparent renderers are visible, needs to happen after CreateDrawData
                         }
                     }
                     renderContext.SetupCameraProperties(camera, m_FrameSettings.enableStereo);