Merge pull request #1420 from Unity-Technologies/Solve-issue-with-motion-blur

HDRP: Solve issue with motion blur - Move object velocity render befo…

com.unity.render-pipelines.high-definition/HDRP/HDRenderPipeline.cs

                     bool forcePrepassForDecals = m_DbufferManager.vsibleDecalCount > 0;
                     RenderDepthPrepass(m_CullResults, hdCamera, renderContext, cmd, forcePrepassForDecals);
 
-                    RenderObjectsVelocity(m_CullResults, hdCamera, renderContext, cmd);
-
                     // This will bind the depth buffer if needed for DBuffer)
                     RenderDBuffer(hdCamera, cmd);
 
                     CopyDepthBufferIfNeeded(cmd);
                     RenderDepthPyramid(hdCamera, cmd, renderContext, FullScreenDebugMode.DepthPyramid);
 
+                    // TODO: In the future we will render object velocity at the same time as depth prepass (we need C++ modification for this)
+                    // Once the C++ change is here we will first render all object without motion vector then motion vector object
+                    // We can't currently render object velocity after depth prepass because if there is no depth prepass we can have motion vector write that should have been rejected
+                    RenderObjectsVelocity(m_CullResults, hdCamera, renderContext, cmd);
                     RenderCameraVelocity(m_CullResults, hdCamera, renderContext, cmd);
 
                     // Depth texture is now ready, bind it (Depth buffer could have been bind before if DBuffer is enable)