HDRenderPipeline: Add BlendMask tiling support

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/LayeredLit/Editor/LayeredLitUI.cs

             public readonly GUIContent layerMapMaskText = new GUIContent("Layer Mask", "Layer mask");
             public readonly GUIContent vertexColorModeText = new GUIContent("Vertex Color Mode", "Mode multiply: vertex color is multiply with the mask. Mode additive: vertex color values are remapped between -1 and 1 and added to the mask (neutral at 0.5 vertex color).");
             public readonly GUIContent layerCountText = new GUIContent("Layer Count", "Number of layers.");
+            public readonly GUIContent layerTilingBlendMaskText = new GUIContent("Tiling", "Tiling for the blend mask.");
+            
             public readonly GUIContent layerTilingText = new GUIContent("Tiling", "Tiling factor applied to UVSet");
             public readonly GUIContent layerTexWorldScaleText = new GUIContent("Tiling", "Tiling factor applied to Planar/Trilinear mapping");
             public readonly GUIContent UVBaseText = new GUIContent("Base UV Mapping", "Base UV Mapping mode of the layer.");
         MaterialProperty[] layerUVDetail = new MaterialProperty[kMaxLayerCount];
         MaterialProperty[] layerUVDetailsMappingMask = new MaterialProperty[kMaxLayerCount];
 
+
+        const string kLayerTilingBlendMask = "_LayerTilingBlendMask";
+        MaterialProperty layerTilingBlendMask = null;
         const string kLayerTiling = "_LayerTiling";
         MaterialProperty[] layerTiling = new MaterialProperty[kMaxLayerCount];
         const string kkUseMainLayerInfluence = "_UseMainLayerInfluence";
 
             useMainLayerInfluence = FindProperty(kkUseMainLayerInfluence, props);
             useHeightBasedBlend = FindProperty(kUseHeightBasedBlend, props);
-            useDensityMode = FindProperty(kUseDensityMode, props);            
+            useDensityMode = FindProperty(kUseDensityMode, props);
+
+            layerTilingBlendMask = FindProperty(kLayerTilingBlendMask, props);
            
             for (int i = 0; i < kMaxLayerCount; ++i)
             {
                 layerChanged = true;
             }
 
+
+
+            if (((LayerUVBaseMapping)layerUVBase[0].floatValue == LayerUVBaseMapping.Planar) ||
+                ((LayerUVBaseMapping)layerUVBase[0].floatValue == LayerUVBaseMapping.Triplanar))
+            {
+                // for now reuse settings from main layer
+            }
+            else
+            {
+                EditorGUI.indentLevel++;
+                m_MaterialEditor.ShaderProperty(layerTilingBlendMask, styles.layerTilingBlendMaskText);
+                EditorGUI.indentLevel--;
+            }
 
             EditorGUI.BeginChangeCheck();
             EditorGUI.showMixedValue = useMainLayerInfluence.hasMixedValue;

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/LayeredLit/LayeredLit.shader

         _OpacityAsDensity2("_OpacityAsDensity2", Range(0, 1.0)) = 0.0
         _OpacityAsDensity3("_OpacityAsDensity3", Range(0, 1.0)) = 0.0
 
-        _LayerTiling0("LayerTiling0", Float) = 1
-        _LayerTiling1("LayerTiling1", Float) = 1
-        _LayerTiling2("LayerTiling2", Float) = 1
-        _LayerTiling3("LayerTiling3", Float) = 1
+        _LayerTilingBlendMask("_LayerTilingBlendMask", Float) = 1
+        _LayerTiling0("_LayerTiling0", Float) = 1
+        _LayerTiling1("_LayerTiling1", Float) = 1
+        _LayerTiling2("_LayerTiling2", Float) = 1
+        _LayerTiling3("_LayerTiling3", Float) = 1
 
         _DistortionVectorMap("DistortionVectorMap", 2D) = "black" {}
 

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/LayeredLit/LayeredLitTessellation.shader

         _OpacityAsDensity2("_OpacityAsDensity2", Range(0, 1.0)) = 0.0
         _OpacityAsDensity3("_OpacityAsDensity3", Range(0, 1.0)) = 0.0
 
-        _LayerTiling0("LayerTiling0", Float) = 1
-        _LayerTiling1("LayerTiling1", Float) = 1
-        _LayerTiling2("LayerTiling2", Float) = 1
-        _LayerTiling3("LayerTiling3", Float) = 1
+        _LayerTilingBlendMask("_LayerTilingBlendMask", Float) = 1
+        _LayerTiling0("_LayerTiling0", Float) = 1
+        _LayerTiling1("_LayerTiling1", Float) = 1
+        _LayerTiling2("_LayerTiling2", Float) = 1
+        _LayerTiling3("_LayerTiling3", Float) = 1
 
         _DistortionVectorMap("DistortionVectorMap", 2D) = "black" {}
 

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/LitData.hlsl

     LayerUV details1;
     LayerUV details2;
     LayerUV details3;
+
+    // Dedicated for blend mask
+    LayerUV blendMask;
 #endif
 
     // triplanar weight
 
     // Be sure that the compiler is aware that we don't touch UV1 to UV3 for main layer so it can optimize code
     _UVMappingMask0.yzw = float3(0.0, 0.0, 0.0);
-    ComputeLayerTexCoord0(  texCoord0, texCoord1, texCoord2, texCoord3, 
+    // Note: Our BlendMask use the same uv mapping than the base layer but with its own tiling.
+    // Here we get a first time the base0 but with _LayerTilingBlendMask. Save the result and recall the function regularly for the main layer.
+    // It is just to share code.
+    ComputeLayerTexCoord0(  texCoord0, float2(0.0, 0.0), float2(0.0, 0.0), float2(0.0, 0.0),
+                            positionWS, normalWS, isTriplanar, layerTexCoord, _LayerTilingBlendMask);
+
+    layerTexCoord.blendMask = layerTexCoord.base0;
+
+    ComputeLayerTexCoord0(  texCoord0, float2(0.0, 0.0), float2(0.0, 0.0), float2(0.0, 0.0),
                             positionWS, normalWS, isTriplanar, layerTexCoord, _LayerTiling0);
 
     isTriplanar = false;
     // Blend mask are Main Layer A - Layer 1 R - Layer 2 G - Layer 3 B
     // Value for main layer is not use for blending itself but for alternate weighting like density.
     // Settings this specific Main layer blend mask in alpha allow to be transparent in case we don't use it and 1 is provide by default.
-    float4 blendMasks = useLodSampling ? SAMPLE_LAYER_TEXTURE2D_LOD(_LayerMaskMap, sampler_LayerMaskMap, layerTexCoord.base0, lod) : SAMPLE_LAYER_TEXTURE2D(_LayerMaskMap, sampler_LayerMaskMap, layerTexCoord.base0);
+    float4 blendMasks = useLodSampling ? SAMPLE_LAYER_TEXTURE2D_LOD(_LayerMaskMap, sampler_LayerMaskMap, layerTexCoord.blendMask, lod) : SAMPLE_LAYER_TEXTURE2D(_LayerMaskMap, sampler_LayerMaskMap, layerTexCoord.blendMask);
 
 #if defined(_LAYER_MASK_VERTEX_COLOR_MUL)
     blendMasks *= vertexColor;

Assets/ScriptableRenderLoop/HDRenderPipeline/Material/Lit/LitProperties.hlsl

 float _InheritBaseColorThreshold1;
 float _InheritBaseColorThreshold2;
 float _InheritBaseColorThreshold3;
+float _LayerTilingBlendMask;
 PROP_DECL(float, _LayerTiling);
 
 float3 _EmissiveColor;