Rename: _LayerMaskMap -> _Control because the terrain uses it.

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

         }
 
         // Layer options
-        MaterialProperty layerMaskMap = null;
-        const string kLayerMaskMap = "_LayerMaskMap";
         MaterialProperty layerInfluenceMaskMap = null;
         const string kLayerInfluenceMaskMap = "_LayerInfluenceMaskMap";
         MaterialProperty UVBlendMask = null;
         {
             base.FindMaterialEmissiveProperties(props);
 
-            layerMaskMap = FindProperty(kLayerMaskMap, props);
             layerInfluenceMaskMap = FindProperty(kLayerInfluenceMaskMap, props);
             UVBlendMask = FindProperty(kUVBlendMask, props);
             UVMappingMaskBlendMask = FindProperty(kUVMappingMaskBlendMask, props);
             EditorGUI.indentLevel++;
             GUILayout.Label(styles.layersText, EditorStyles.boldLabel);
 
-            m_MaterialEditor.TexturePropertySingleLine(styles.layerMapMaskText, layerMaskMap);
-
             EditorGUI.indentLevel++;
             m_MaterialEditor.ShaderProperty(UVBlendMask, styles.UVBlendMaskText);
             UVBaseMapping uvBlendMask = (UVBaseMapping)UVBlendMask.floatValue;
             {
                 m_MaterialEditor.ShaderProperty(texWorldScaleBlendMask, styles.layerTexWorldScaleText);
             }
-            m_MaterialEditor.TextureScaleOffsetProperty(layerMaskMap);
             EditorGUI.indentLevel--;
 
             EditorGUI.BeginChangeCheck();

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

 {
     Properties
     {
+        [HideInInspector] _Control("Control (RGBA)", 2D) = "red" {}
+
+        // TODO: route values from terrain layers. enable _DENSITY_MODE if any of these enabled.
+        [HideInInspector] [ToggleUI] _OpacityAsDensity0("_OpacityAsDensity0", Float) = 0.0
+        [HideInInspector] [ToggleUI] _OpacityAsDensity1("_OpacityAsDensity1", Float) = 0.0
+        [HideInInspector] [ToggleUI] _OpacityAsDensity2("_OpacityAsDensity2", Float) = 0.0
+        [HideInInspector] [ToggleUI] _OpacityAsDensity3("_OpacityAsDensity3", Float) = 0.0
+
         // Following set of parameters represent the parameters node inside the MaterialGraph.
         // They are use to fill a SurfaceData. With a MaterialGraph this should not exist.
 
         // All the following properties exist only in layered lit material
 
         // Layer blending options
-        _LayerMaskMap("LayerMaskMap", 2D) = "white" {}
         _LayerInfluenceMaskMap("LayerInfluenceMaskMap", 2D) = "white" {}
         [ToggleUI] _UseHeightBasedBlend("UseHeightBasedBlend", Float) = 0.0
 
         _InheritBaseColor1("_InheritBaseColor1", Range(0, 1.0)) = 0.0
         _InheritBaseColor2("_InheritBaseColor2", Range(0, 1.0)) = 0.0
         _InheritBaseColor3("_InheritBaseColor3", Range(0, 1.0)) = 0.0
-
-        // TODO: route values from terrain layers. enable _DENSITY_MODE if any of these enabled.
-        [HideInInspector] [ToggleUI] _OpacityAsDensity0("_OpacityAsDensity0", Float) = 0.0
-        [HideInInspector] [ToggleUI] _OpacityAsDensity1("_OpacityAsDensity1", Float) = 0.0
-        [HideInInspector] [ToggleUI] _OpacityAsDensity2("_OpacityAsDensity2", Float) = 0.0
-        [HideInInspector] [ToggleUI] _OpacityAsDensity3("_OpacityAsDensity3", Float) = 0.0
 
         [Enum(UV0, 0, UV1, 1, UV2, 2, UV3, 3, Planar, 4, Triplanar, 5)] _UVBlendMask("UV Set for blendMask", Float) = 0
         [HideInInspector] _UVMappingMaskBlendMask("_UVMappingMaskBlendMask", Color) = (1, 0, 0, 0)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/LayeredLit/TerrainLitData.hlsl

     return diffusionProfileId;
 }
 
+TEXTURE2D(_Control);
+SAMPLER(sampler_Control);
+
 #define SURFACEDATA_BLEND_VECTOR3(surfaceData, name, mask) BlendLayeredVector3(MERGE_NAME(surfaceData, 0) MERGE_NAME(., name), MERGE_NAME(surfaceData, 1) MERGE_NAME(., name), MERGE_NAME(surfaceData, 2) MERGE_NAME(., name), MERGE_NAME(surfaceData, 3) MERGE_NAME(., name), mask);
 #define SURFACEDATA_BLEND_SCALAR(surfaceData, name, mask) BlendLayeredScalar(MERGE_NAME(surfaceData, 0) MERGE_NAME(., name), MERGE_NAME(surfaceData, 1) MERGE_NAME(., name), MERGE_NAME(surfaceData, 2) MERGE_NAME(., name), MERGE_NAME(surfaceData, 3) MERGE_NAME(., name), mask);
 #define SURFACEDATA_BLEND_DIFFUSION_PROFILE(surfaceData, name, mask) BlendLayeredDiffusionProfile(MERGE_NAME(surfaceData, 0) MERGE_NAME(., name), MERGE_NAME(surfaceData, 1) MERGE_NAME(., name), MERGE_NAME(surfaceData, 2) MERGE_NAME(., name), MERGE_NAME(surfaceData, 3) MERGE_NAME(., name), mask);
     // Note: Blend mask have its dedicated mapping and tiling.
     // To share code, we simply call the regular code from the main layer for it then save the result, then do regular call for all layers.
     ComputeLayerTexCoord0(  texCoord0, texCoord1, texCoord2, texCoord3, _UVMappingMaskBlendMask, _UVMappingMaskBlendMask,
-                            _LayerMaskMap_ST.xy, _LayerMaskMap_ST.zw, float2(0.0, 0.0), float2(0.0, 0.0), 1.0, false,
+                            float2(1, 1), float2(0, 0), float2(0.0, 0.0), float2(0.0, 0.0), 1.0, false,
                             positionWS, _TexWorldScaleBlendMask,
                             mappingType, layerTexCoord);
 
 }
 
 // Caution: Blend mask are Layer 1 R - Layer 2 G - Layer 3 B - Main Layer A
-float4 GetBlendMask(LayerTexCoord layerTexCoord, float4 vertexColor, bool useLodSampling = false, float lod = 0)
+float4 GetBlendMask(LayerTexCoord layerTexCoord, float4 vertexColor)
-    float4 blendMasks = useLodSampling ? SAMPLE_UVMAPPING_TEXTURE2D_LOD(_LayerMaskMap, sampler_LayerMaskMap, layerTexCoord.blendMask, lod) : SAMPLE_UVMAPPING_TEXTURE2D(_LayerMaskMap, sampler_LayerMaskMap, layerTexCoord.blendMask);
+    float4 blendMasks = SAMPLE_UVMAPPING_TEXTURE2D(_Control, sampler_Control, layerTexCoord.blendMask);
 
     // Wind uses vertex alpha as an intensity parameter.
     // So in case Layered shader uses wind, we need to hardcode the alpha here so that the main layer can be visible without affecting wind intensity.