Merge pull request #851 from Unity-Technologies/Add-transparent-priority-support

Add transparent priority support

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Unlit/BaseUnlitUI.cs

             public static GUIContent transparentDepthPrepassEnableText = new GUIContent("Enable transparent depth prepass", "It allow to to fill depth buffer to improve sorting");
             public static GUIContent transparentDepthPostpassEnableText = new GUIContent("Enable transparent depth postpass", "It allow to fill depth buffer for postprocess effect like DOF");
             public static GUIContent transparentBackfaceEnableText = new GUIContent("Enable back then front rendering", "It allow to better sort transparent mesh by first rendering back faces then front faces in two separate drawcall");
+
+            public static GUIContent transparentQueuePriorityText = new GUIContent("Transparent Queue Priority", "Allow to define priority (from -100 to +100) to solve sorting issue with transparent");
             public static GUIContent enableTransparentFogText = new GUIContent("Enable fog", "Enable fog on transparent material");
             public static GUIContent enableBlendModePreserveSpecularLightingText = new GUIContent("Blend preserve specular lighting", "Blend mode will only affect diffuse lighting, allowing correct specular lighting (reflection) on transparent object");
 
         protected const string kTransparentDepthPostpassEnable = "_TransparentDepthPostpassEnable";
         protected MaterialProperty transparentBackfaceEnable = null;
         protected const string kTransparentBackfaceEnable = "_TransparentBackfaceEnable";
+        protected MaterialProperty transparentQueuePriority = null;
+        protected const string kTransparentQueuePriority = "_TransparentQueuePriority";
         protected MaterialProperty doubleSidedEnable = null;
         protected const string kDoubleSidedEnable = "_DoubleSidedEnable";
         protected MaterialProperty blendMode = null;
             transparentDepthPostpassEnable = FindProperty(kTransparentDepthPostpassEnable, props, false);
             transparentBackfaceEnable = FindProperty(kTransparentBackfaceEnable, props, false);
 
+            transparentQueuePriority = FindProperty(kTransparentQueuePriority, props, false);
+
             doubleSidedEnable = FindProperty(kDoubleSidedEnable, props, false);
             blendMode = FindProperty(kBlendMode, props, false);
 
             if (transparentBackfaceEnable != null && ((SurfaceType)surfaceType.floatValue == SurfaceType.Transparent))
                 m_MaterialEditor.ShaderProperty(transparentBackfaceEnable, StylesBaseUnlit.transparentBackfaceEnableText);
 
+            if (transparentQueuePriority != null && ((SurfaceType)surfaceType.floatValue == SurfaceType.Transparent))
+            {
+                EditorGUI.BeginChangeCheck();
+                m_MaterialEditor.ShaderProperty(transparentQueuePriority, StylesBaseUnlit.transparentQueuePriorityText);
+                if (EditorGUI.EndChangeCheck())
+                {
+                    transparentQueuePriority.floatValue = Mathf.Clamp((int)transparentQueuePriority.floatValue, -(int)HDRenderQueue.k_TransparentPriorityQueueRange, (int)HDRenderQueue.k_TransparentPriorityQueueRange);
+                }
+            }
+
             // This function must finish with double sided option (see LitUI.cs)
             if (doubleSidedEnable != null)
             {
                 material.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.One);
                 material.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.Zero);
                 material.SetInt("_ZWrite", 1);
-                material.renderQueue = alphaTestEnable ? (int)HDRenderQueue.AlphaTest : -1;
+                material.renderQueue = alphaTestEnable ? (int)HDRenderQueue.Priority.AlphaTest : -1;
             }
             else
             {
-                material.renderQueue = (int)(isPrepass ? HDRenderQueue.PreRefraction : HDRenderQueue.Transparent);
+                material.renderQueue = (int)(isPrepass ? HDRenderQueue.Priority.PreRefraction : HDRenderQueue.Priority.Transparent) + (int)material.GetFloat(kTransparentQueuePriority);
 
                 if (material.HasProperty(kBlendMode))
                 {

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

             "Forward Transparent"
         };
 
-        static readonly RenderQueueRange k_RenderQueue_PreRefraction = new RenderQueueRange { min = (int)HDRenderQueue.PreRefraction, max = (int)HDRenderQueue.Transparent - 1 };
-        static readonly RenderQueueRange k_RenderQueue_Transparent = new RenderQueueRange { min = (int)HDRenderQueue.Transparent, max = (int)HDRenderQueue.Overlay - 1 };
-        static readonly RenderQueueRange k_RenderQueue_AllTransparent = new RenderQueueRange { min = (int)HDRenderQueue.PreRefraction, max = (int)HDRenderQueue.Overlay - 1 };
-
         readonly HDRenderPipelineAsset m_Asset;
 
         DiffusionProfileSettings m_InternalSSSAsset;
 
             var filterSettings = new FilterRenderersSettings(true)
             {
-                renderQueueRange = inRenderQueueRange == null ? RenderQueueRange.opaque : inRenderQueueRange.Value
+                renderQueueRange = inRenderQueueRange == null ? HDRenderQueue.k_RenderQueue_AllOpaque : inRenderQueueRange.Value
             };
 
             if (stateBlock == null)
 
             var filterSettings = new FilterRenderersSettings(true)
             {
-                renderQueueRange = inRenderQueueRange == null ? k_RenderQueue_AllTransparent : inRenderQueueRange.Value
+                renderQueueRange = inRenderQueueRange == null ? HDRenderQueue.k_RenderQueue_AllTransparent : inRenderQueueRange.Value
             };
 
             if (stateBlock == null)
                 {
                     // We render first the opaque object as opaque alpha tested are more costly to render and could be reject by early-z (but not Hi-z as it is disable with clip instruction)
                     // This is handled automatically with the RenderQueue value (OpaqueAlphaTested have a different value and thus are sorted after Opaque)
-                    RenderOpaqueRenderList(cull, camera, renderContext, cmd, m_DepthOnlyAndDepthForwardOnlyPassNames, 0, RenderQueueRange.opaque, m_DepthStateOpaque);
+                    RenderOpaqueRenderList(cull, camera, renderContext, cmd, m_DepthOnlyAndDepthForwardOnlyPassNames, 0, HDRenderQueue.k_RenderQueue_AllOpaque, m_DepthStateOpaque);
-                    RenderOpaqueRenderList(cull, camera, renderContext, cmd, m_DepthForwardOnlyPassNames, 0, RenderQueueRange.opaque, m_DepthStateOpaque);
+                    RenderOpaqueRenderList(cull, camera, renderContext, cmd, m_DepthForwardOnlyPassNames, 0, HDRenderQueue.k_RenderQueue_AllOpaque, m_DepthStateOpaque);
 
                     // Render Alpha test only if requested
                     if (addAlphaTestedOnly)
                 if (m_CurrentDebugDisplaySettings.IsDebugDisplayEnabled())
                 {
                     // When doing debug display, the shader has the clip instruction regardless of the depth prepass so we can use regular depth test.
-                    RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferDebugDisplayName, m_currentRendererConfigurationBakedLighting, RenderQueueRange.opaque, m_DepthStateOpaque);
+                    RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferDebugDisplayName, m_currentRendererConfigurationBakedLighting, HDRenderQueue.k_RenderQueue_AllOpaque, m_DepthStateOpaque);
-                        var rangeOpaqueNoAlphaTest = new RenderQueueRange { min = (int)RenderQueue.Geometry, max = (int)RenderQueue.AlphaTest - 1 };
-                        var rangeOpaqueAlphaTest = new RenderQueueRange { min = (int)RenderQueue.AlphaTest, max = (int)RenderQueue.GeometryLast - 1 };
-
-                        RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferName, m_currentRendererConfigurationBakedLighting, rangeOpaqueNoAlphaTest, m_FrameSettings.enableAlphaTestOnlyInDeferredPrepass ? m_DepthStateOpaque : m_DepthStateOpaqueWithPrepass);
+                        RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferName, m_currentRendererConfigurationBakedLighting, HDRenderQueue.k_RenderQueue_OpaqueNoAlphaTest, m_FrameSettings.enableAlphaTestOnlyInDeferredPrepass ? m_DepthStateOpaque : m_DepthStateOpaqueWithPrepass);
-                        RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferWithPrepassName, m_currentRendererConfigurationBakedLighting, rangeOpaqueAlphaTest, m_DepthStateOpaqueWithPrepass);
+                        RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferWithPrepassName, m_currentRendererConfigurationBakedLighting, HDRenderQueue.k_RenderQueue_OpaqueAlphaTest, m_DepthStateOpaqueWithPrepass);
-                        RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferName, m_currentRendererConfigurationBakedLighting, RenderQueueRange.opaque, m_DepthStateOpaque);
+                        RenderOpaqueRenderList(cull, camera, renderContext, cmd, HDShaderPassNames.s_GBufferName, m_currentRendererConfigurationBakedLighting, HDRenderQueue.k_RenderQueue_AllOpaque, m_DepthStateOpaque);
                     }
                 }
             }
                     CoreUtils.SetRenderTarget(cmd, m_CameraColorBufferRT, m_CameraDepthStencilBufferRT);
 
                     var passNames = m_CurrentDebugDisplaySettings.IsDebugDisplayEnabled() ? m_AllTransparentDebugDisplayPassNames : m_AllTransparentPassNames;
-                    RenderTransparentRenderList(cullResults, camera, renderContext, cmd, passNames, m_currentRendererConfigurationBakedLighting, pass == ForwardPass.PreRefraction ? k_RenderQueue_PreRefraction : k_RenderQueue_Transparent);
+                    RenderTransparentRenderList(cullResults, camera, renderContext, cmd, passNames, m_currentRendererConfigurationBakedLighting, pass == ForwardPass.PreRefraction ? HDRenderQueue.k_RenderQueue_PreRefraction : HDRenderQueue.k_RenderQueue_Transparent);
                 }
             }
         }
                 }
                 else
                 {
-                    RenderTransparentRenderList(cullResults, camera, renderContext, cmd, m_ForwardErrorPassNames, 0, pass == ForwardPass.PreRefraction ? k_RenderQueue_PreRefraction : k_RenderQueue_Transparent, null, m_ErrorMaterial);
+                    RenderTransparentRenderList(cullResults, camera, renderContext, cmd, m_ForwardErrorPassNames, 0, pass == ForwardPass.PreRefraction ? HDRenderQueue.k_RenderQueue_PreRefraction : HDRenderQueue.k_RenderQueue_Transparent, null, m_ErrorMaterial);
                 }
             }
         }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderQueue.cs

 
 namespace UnityEngine.Experimental.Rendering.HDPipeline
 {
-    public enum HDRenderQueue
+    // In HD we don't expose HDRenderQueue instead we create as much value as needed in the enum for our different pass
+    // and use inspector to manipulate the value.
+    // In the case of transparent we want to use RenderQueue to help with sorting. We define a neutral value for the RenderQueue and priority going from -X to +X
+    // going from -X to +X instead of 0 to +X as builtin Unity is better for artists as they can decide late to sort behind or in front of the scene.
+
+    public class HDRenderQueue
-        Background = UnityEngine.Rendering.RenderQueue.Background,
-        Geometry = UnityEngine.Rendering.RenderQueue.Geometry,
-        AlphaTest = UnityEngine.Rendering.RenderQueue.AlphaTest,
-        GeometryLast = UnityEngine.Rendering.RenderQueue.GeometryLast,
-        PreRefraction = 2750,
-        Transparent = UnityEngine.Rendering.RenderQueue.Transparent,
-        Overlay = UnityEngine.Rendering.RenderQueue.Overlay
+        public const int k_TransparentPriorityQueueRange = 100;
+
+        public enum Priority
+        {
+            Background = UnityEngine.Rendering.RenderQueue.Background,
+            Geometry = UnityEngine.Rendering.RenderQueue.Geometry,
+            AlphaTest = UnityEngine.Rendering.RenderQueue.AlphaTest,
+            GeometryLast = UnityEngine.Rendering.RenderQueue.GeometryLast,
+            // For transparent pass we define a range of 200 value to define the priority
+            // Warning: Be sure no range are overlapping
+            PreRefractionFirst = 2750 - k_TransparentPriorityQueueRange,
+            PreRefraction = 2750,
+            PreRefractionLast = 2750 + k_TransparentPriorityQueueRange,
+            TransparentFirst = UnityEngine.Rendering.RenderQueue.Transparent - k_TransparentPriorityQueueRange,
+            Transparent = UnityEngine.Rendering.RenderQueue.Transparent,
+            TransparentLast = UnityEngine.Rendering.RenderQueue.Transparent + k_TransparentPriorityQueueRange,
+            Overlay = UnityEngine.Rendering.RenderQueue.Overlay
+        }
+
+        public static readonly RenderQueueRange k_RenderQueue_OpaqueNoAlphaTest = new RenderQueueRange { min = (int)Priority.Geometry, max = (int)Priority.AlphaTest - 1 };
+        public static readonly RenderQueueRange k_RenderQueue_OpaqueAlphaTest = new RenderQueueRange { min = (int)Priority.AlphaTest, max = (int)Priority.GeometryLast };
+        public static readonly RenderQueueRange k_RenderQueue_AllOpaque = new RenderQueueRange { min = (int)Priority.Geometry, max = (int)Priority.GeometryLast };
+
+        public static readonly RenderQueueRange k_RenderQueue_PreRefraction = new RenderQueueRange { min = (int)Priority.PreRefractionFirst, max = (int)Priority.PreRefractionLast };
+        public static readonly RenderQueueRange k_RenderQueue_Transparent = new RenderQueueRange { min = (int)Priority.TransparentFirst, max = (int)Priority.TransparentLast };
+        public static readonly RenderQueueRange k_RenderQueue_AllTransparent = new RenderQueueRange { min = (int)Priority.PreRefractionFirst, max = (int)Priority.TransparentLast };
+
+        public static readonly RenderQueueRange k_RenderQueue_All = new RenderQueueRange { min = 0, max = 5000 };
     }
 }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/LayeredLit/LayeredLit.shader

         [ToggleUI] _AlphaCutoffEnable("Alpha Cutoff Enable", Float) = 0.0
 
         _AlphaCutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
+        _TransparentQueuePriority("_TransparentQueuePriority", Float) = 0
 
         // Stencil state
         [HideInInspector] _StencilRef("_StencilRef", Int) = 2 // StencilLightingUsage.RegularLighting

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/LayeredLit/LayeredLitTessellation.shader

         [ToggleUI] _AlphaCutoffEnable("Alpha Cutoff Enable", Float) = 0.0
 
         _AlphaCutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
+        _TransparentQueuePriority("_TransparentQueuePriority", Float) = 0
 
         // Stencil state
         [HideInInspector] _StencilRef("_StencilRef", Int) = 2 // StencilLightingUsage.RegularLighting

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.shader

         [ToggleUI] _TransparentDepthPrepassEnable("_TransparentDepthPrepassEnable", Float) = 0.0
         [ToggleUI] _TransparentBackfaceEnable("_TransparentBackfaceEnable", Float) = 0.0
         [ToggleUI] _TransparentDepthPostpassEnable("_TransparentDepthPostpassEnable", Float) = 0.0
+        _TransparentQueuePriority("_TransparentQueuePriority", Float) = 0
 
         // Transparency
         [Enum(None, 0, Plane, 1, Sphere, 2)]_RefractionMode("Refraction Mode", Int) = 0

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitTessellation.shader

         [ToggleUI] _TransparentDepthPrepassEnable("_TransparentDepthPrepassEnable", Float) = 0.0
         [ToggleUI] _TransparentBackfaceEnable("_TransparentBackfaceEnable", Float) = 0.0
         [ToggleUI] _TransparentDepthPostpassEnable("_TransparentDepthPostpassEnable", Float) = 0.0
+        _TransparentQueuePriority("_TransparentQueuePriority", Float) = 0
 
         // Transparency
         [Enum(None, 0, Plane, 1, Sphere, 2)]_RefractionMode("Refraction Mode", Int) = 0

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Unlit/Unlit.shader

 
         [ToggleUI]  _AlphaCutoffEnable("Alpha Cutoff Enable", Float) = 0.0
         _AlphaCutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5
+        _TransparentQueuePriority("_TransparentQueuePriority", Float) = 0
 
         // Blending state
         [HideInInspector] _SurfaceType("__surfacetype", Float) = 0.0