First draft of SSS and Transmisison UI

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/LayeredLit/LayeredLitUI.cs

             CoreUtils.SetKeyword(material, "_DENSITY_MODE", useDensityModeEnable);
 
             BaseLitGUI.MaterialId materialId = (BaseLitGUI.MaterialId)material.GetFloat(kMaterialID);
-            BaseLitGUI.SSSAndTransmissionType sssAndTransmissionType = (BaseLitGUI.SSSAndTransmissionType)material.GetFloat(kSSSAndTransmissionType);
-
-            if (materialId == BaseLitGUI.MaterialId.LitSSSAndTransmission)
-            {
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_SUBSURFACE_SCATTERING", sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission || sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitSSSOnly);
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_TRANSMISSION", sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission || sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitTransmissionOnly);
-            }
-            else
-            {
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_SUBSURFACE_SCATTERING", false);
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_TRANSMISSION", false);
-            }
+            CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_SUBSURFACE_SCATTERING", materialId == BaseLitGUI.MaterialId.LitSSS);
+            CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_TRANSMISSION", materialId == BaseLitGUI.MaterialId.LitTranslucent || (materialId == BaseLitGUI.MaterialId.LitSSS && material.GetFloat(kTransmissionEnable) > 0.0f));
         }
 
         public override void OnGUI(MaterialEditor materialEditor, MaterialProperty[] props)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Lit/BaseLitUI.cs

 
             // Material ID
             public static GUIContent materialIDText = new GUIContent("Material type", "Select a material feature to enable on top of regular material");
-            public static GUIContent SSSAndTransmissionTypeText = new GUIContent("SSS and Transmission type", "Subsurface Scattering for translucent materials such as skin, vegetation, fruit, marble, wax and milk., Transmission for back lighting");
+            public static GUIContent transmissionEnableText = new GUIContent("Enable Transmission", "Enable Transmission for getting  back lighting");
 
             // Per pixel displacement
             public static GUIContent ppdMinSamplesText = new GUIContent("Minimum steps", "Minimum steps (texture sample) to use with per pixel displacement mapping");
 
         public enum MaterialId
         {
-            LitSSSAndTransmission = 0,
+            LitSSS = 0,
-            LitSpecular = 4
-        };
-
-        public enum SSSAndTransmissionType
-        {
-            LitSSSAndTransmission = 0,
-            LitSSSOnly = 1,
-            LitTransmissionOnly = 2,
+            LitSpecular = 4,
+            LitTranslucent = 5
         };
 
         public enum HeightmapParametrization
         // Material ID
         protected MaterialProperty materialID  = null;
         protected const string kMaterialID = "_MaterialID";
-        protected MaterialProperty sssAndTransmissionType = null;
-        protected const string kSSSAndTransmissionType = "_SSSAndTransmissionType";        
+        protected MaterialProperty transmissionEnable = null;
+        protected const string kTransmissionEnable = "_TransmissionEnable";
 
         protected const string kStencilRef = "_StencilRef";
         protected const string kStencilWriteMask = "_StencilWriteMask";
 
             // MaterialID
             materialID = FindProperty(kMaterialID, props);
-            sssAndTransmissionType = FindProperty(kSSSAndTransmissionType, props);      
+            transmissionEnable = FindProperty(kTransmissionEnable, props);
 
             displacementMode = FindProperty(kDisplacementMode, props);
             displacementLockObjectScale = FindProperty(kDisplacementLockObjectScale, props);
             }
 
             m_MaterialEditor.ShaderProperty(materialID, StylesBaseLit.materialIDText);
-
-            if ((int)materialID.floatValue == (int)BaseLitGUI.MaterialId.LitSSSAndTransmission)
-            {
-                m_MaterialEditor.ShaderProperty(sssAndTransmissionType, StylesBaseLit.SSSAndTransmissionTypeText);                
-            }                
 
             m_MaterialEditor.ShaderProperty(supportDBuffer, StylesBaseLit.supportDBufferText);
 
 
             // Set the reference value for the stencil test.
             int stencilRef = (int)StencilLightingUsage.RegularLighting;
-            if ((int)material.GetFloat(kMaterialID) == (int)BaseLitGUI.MaterialId.LitSSSAndTransmission)
+            if ((int)material.GetFloat(kMaterialID) == (int)BaseLitGUI.MaterialId.LitSSS)
-                if ((int)material.GetFloat(kSSSAndTransmissionType) == (int)BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission ||
-                    (int)material.GetFloat(kSSSAndTransmissionType) == (int)BaseLitGUI.SSSAndTransmissionType.LitSSSOnly)
-                {
-                    stencilRef = (int)StencilLightingUsage.SplitLighting;
-                }
+                stencilRef = (int)StencilLightingUsage.SplitLighting;
             }
             // As we tag both during velocity pass and Gbuffer pass we need a separate state and we need to use the write mask
             material.SetInt(kStencilRef, stencilRef);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Lit/LitUI.cs

 
             // clear coat
             coatMask = FindProperty(kCoatMask, props);
-            coatMaskMap = FindProperty(kCoatMaskMap, props);            
+            coatMaskMap = FindProperty(kCoatMaskMap, props);
 
             // Transparency
             refractionMode = FindProperty(kRefractionMode, props, false);
                     diffusionProfileID[layerIndex].floatValue = profileID;
             }
 
-            if ((int)sssAndTransmissionType.floatValue == (int)BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission || (int)sssAndTransmissionType.floatValue == (int)BaseLitGUI.SSSAndTransmissionType.LitSSSOnly)
+            if ((int)materialID.floatValue == (int)BaseLitGUI.MaterialId.LitSSS)
+                m_MaterialEditor.ShaderProperty(transmissionEnable, StylesBaseLit.transmissionEnableText);
+
-            if ((int)sssAndTransmissionType.floatValue == (int)BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission || (int)sssAndTransmissionType.floatValue == (int)BaseLitGUI.SSSAndTransmissionType.LitTransmissionOnly)
+            if ((int)materialID.floatValue == (int)BaseLitGUI.MaterialId.LitSSS ||
+                ((int)materialID.floatValue == (int)BaseLitGUI.MaterialId.LitTranslucent && transmissionEnable.floatValue > 0.0f))
             {
                 m_MaterialEditor.TexturePropertySingleLine(Styles.thicknessMapText, thicknessMap[layerIndex]);
                 if (thicknessMap[layerIndex].textureValue != null)
 
             switch ((BaseLitGUI.MaterialId)materialID.floatValue)
             {
-                case BaseLitGUI.MaterialId.LitSSSAndTransmission:
+                case BaseLitGUI.MaterialId.LitSSS:
+                case BaseLitGUI.MaterialId.LitTranslucent:
                     ShaderSSSAndTransmissionInputGUI(material, layerIndex);
                     break;
                 case BaseLitGUI.MaterialId.LitStandard:
             if (!isLayeredLit)
             {
                 ShaderClearCoatInputGUI();
-            }            
+            }
 
             EditorGUILayout.Space();
 
             }
 
             BaseLitGUI.MaterialId materialId = (BaseLitGUI.MaterialId)material.GetFloat(kMaterialID);
-            BaseLitGUI.SSSAndTransmissionType sssAndTransmissionType = (BaseLitGUI.SSSAndTransmissionType)material.GetFloat(kSSSAndTransmissionType);
-
-            if (materialId == BaseLitGUI.MaterialId.LitSSSAndTransmission)
-            {
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_SUBSURFACE_SCATTERING", sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission || sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitSSSOnly);
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_TRANSMISSION", sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitSSSAndTransmission || sssAndTransmissionType == BaseLitGUI.SSSAndTransmissionType.LitTransmissionOnly);
-            }
-            else
-            {
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_SUBSURFACE_SCATTERING", false);
-                CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_TRANSMISSION", false);
-            }
+            CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_SUBSURFACE_SCATTERING", materialId == BaseLitGUI.MaterialId.LitSSS);
+            CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_TRANSMISSION", materialId == BaseLitGUI.MaterialId.LitTranslucent || (materialId == BaseLitGUI.MaterialId.LitSSS && material.GetFloat(kTransmissionEnable) > 0.0f));
 
             CoreUtils.SetKeyword(material, "_MATERIAL_FEATURE_ANISOTROPY", materialId == BaseLitGUI.MaterialId.LitAniso);
             // No material Id for clear coat, just test the attribute

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

         [HideInInspector] _DoubleSidedConstants("_DoubleSidedConstants", Vector) = (1, 1, -1, 0)
 
         // For layering, due to combinatorial explosion, we only support SSS/Transmission and Standard. We let other case for the shader graph
-        [Enum(Subsurface Scattering and Transmissison, 0, Standard, 1)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
-        [Enum(Both, 0, SSS only, 1, Transmission only, 2)] _SSSAndTransmissionType("SSSandTransmissionType", Int) = 0 // SSSandTransmissionType.Both
+        [Enum(Subsurface Scattering, 0, Standard, 1, Translucent, 5)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
+        [ToggleUI] _TransmissionEnable("_TransmissionEnable", Float) = 1.0
 
         [Enum(None, 0, Vertex displacement, 1, Pixel displacement, 2)] _DisplacementMode("DisplacementMode", Int) = 0
         [ToggleUI] _DisplacementLockObjectScale("displacement lock object scale", Float) = 1.0

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

         [HideInInspector] _DoubleSidedConstants("_DoubleSidedConstants", Vector) = (1, 1, -1, 0)
 
         // For layering, due to combinatorial explosion, we only support SSS/Transmission and Standard. We let other case for the shader graph
-        [Enum(Subsurface Scattering and Transmissison, 0, Standard, 1)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
-        [Enum(Both, 0, SSS only, 1, Transmission only, 2)] _SSSAndTransmissionType("SSSandTransmissionType", Int) = 0 // SSSandTransmissionType.Both
+        [Enum(Subsurface Scattering, 0, Standard, 1, Translucent, 5)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
+        [ToggleUI] _TransmissionEnable("_TransmissionEnable", Float) = 1.0
 
         [Enum(None, 0, Tessellation displacement, 3)] _DisplacementMode("DisplacementMode", Int) = 3
         [ToggleUI] _DisplacementLockObjectScale("displacement lock object scale", Float) = 1.0

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

         // Following enum should be material feature flags (i.e bitfield), however due to Gbuffer encoding constrain many combination exclude each other
         // so we use this enum as "material ID" which can be interpreted as preset of bitfield of material feature
         // The only material feature flag that can be added in all cases is clear coat
-        [Enum(Subsurface Scattering and Transmissison, 0, Standard, 1, Anisotropy, 2, Iridescence, 3, Specular Color, 4)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
-        [Enum(Both, 0, SSS only, 1, Transmission only, 2)] _SSSAndTransmissionType("SSSandTransmissionType", Int) = 0 // SSSandTransmissionType.Both
+        [Enum(Subsurface Scattering, 0, Standard, 1, Anisotropy, 2, Iridescence, 3, Specular Color, 4, Translucent, 5)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
+        [ToggleUI] _TransmissionEnable("_TransmissionEnable", Float) = 1.0
 
         [Enum(None, 0, Vertex displacement, 1, Pixel displacement, 2)] _DisplacementMode("DisplacementMode", Int) = 0
         [ToggleUI] _DisplacementLockObjectScale("displacement lock object scale", Float) = 1.0

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

         // Following enum should be material feature flags (i.e bitfield), however due to Gbuffer encoding constrain many combination exclude each other
         // so we use this enum as "material ID" which can be interpreted as preset of bitfield of material feature
         // The only material feature flag that can be added in all cases is clear coat
-        [Enum(Subsurface Scattering and Transmissison, 0, Standard, 1, Anisotropy, 2, Iridescence, 3, Specular Color, 4)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
-        [Enum(Both, 0, SSS only, 1, Transmission only, 2)] _SSSAndTransmissionType("SSSandTransmissionType", Int) = 0 // SSSandTransmissionType.Both
+        [Enum(Subsurface Scattering, 0, Standard, 1, Anisotropy, 2, Iridescence, 3, Specular Color, 4, Translucent, 5)] _MaterialID("MaterialId", Int) = 1 // MaterialId.Standard
+        [ToggleUI] _TransmissionEnable("_TransmissionEnable", Float) = 1.0
 
         [Enum(None, 0, Tessellation displacement, 3)] _DisplacementMode("DisplacementMode", Int) = 3
         [ToggleUI] _DisplacementLockObjectScale("displacement lock object scale", Float) = 1.0