Remove thickness maps.

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

         _DiffusionProfile2("Diffusion Profile2", Int) = 0
         _DiffusionProfile3("Diffusion Profile3", Int) = 0
 
-        _Thickness0("Thickness", Range(0.0, 1.0)) = 1.0
-        _Thickness1("Thickness", Range(0.0, 1.0)) = 1.0
-        _Thickness2("Thickness", Range(0.0, 1.0)) = 1.0
-        _Thickness3("Thickness", Range(0.0, 1.0)) = 1.0
-
-        _ThicknessMap0("Thickness Map", 2D) = "white" {}
-        _ThicknessMap1("Thickness Map", 2D) = "white" {}
-        _ThicknessMap2("Thickness Map", 2D) = "white" {}
-        _ThicknessMap3("Thickness Map", 2D) = "white" {}
-
-        _ThicknessRemap0("Thickness Remap", Vector) = (0, 1, 0, 0)
-        _ThicknessRemap1("Thickness Remap", Vector) = (0, 1, 0, 0)
-        _ThicknessRemap2("Thickness Remap", Vector) = (0, 1, 0, 0)
-        _ThicknessRemap3("Thickness Remap", Vector) = (0, 1, 0, 0)
-
         // All the following properties exist only in layered lit material
 
         // Layer blending options
     #pragma shader_feature _HEIGHTMAP1
     #pragma shader_feature _HEIGHTMAP2
     #pragma shader_feature _HEIGHTMAP3
-    #pragma shader_feature _THICKNESSMAP0
-    #pragma shader_feature _THICKNESSMAP1
-    #pragma shader_feature _THICKNESSMAP2
-    #pragma shader_feature _THICKNESSMAP3
 
     #pragma shader_feature _MAIN_LAYER_INFLUENCE_MODE
     #pragma shader_feature _INFLUENCEMASK_MAP

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

 #define SAMPLER_HEIGHTMAP_IDX sampler_HeightMap3
 #endif
 
-#if defined(_THICKNESSMAP0)
-#define SAMPLER_THICKNESSMAP_IDX sampler_ThicknessMap0
-#elif defined(_THICKNESSMAP1)
-#define SAMPLER_THICKNESSMAP_IDX sampler_ThicknessMap1
-#elif defined(_THICKNESSMAP2)
-#define SAMPLER_THICKNESSMAP_IDX sampler_ThicknessMap2
-#elif defined(_THICKNESSMAP3)
-#define SAMPLER_THICKNESSMAP_IDX sampler_ThicknessMap3
-#endif
-
 // Define a helper macro
 
 #define ADD_ZERO_IDX(Name) Name##0
 #endif
 #ifdef _NORMALMAP_TANGENT_SPACE0
 #define _NORMALMAP_TANGENT_SPACE_IDX
-#endif
-#ifdef _THICKNESSMAP0
-#define _THICKNESSMAP_IDX
 #endif
 #ifdef _MASKMAP0
 #define _MASKMAP_IDX
 #undef ADD_IDX
 #undef _NORMALMAP_IDX
 #undef _NORMALMAP_TANGENT_SPACE_IDX
-#undef _THICKNESSMAP_IDX
 #undef _MASKMAP_IDX
 #undef _BENTNORMALMAP_IDX
 
 #endif
 #ifdef _NORMALMAP_TANGENT_SPACE1
 #define _NORMALMAP_TANGENT_SPACE_IDX
-#endif
-#ifdef _THICKNESSMAP1
-#define _THICKNESSMAP_IDX
 #endif
 #ifdef _MASKMAP1
 #define _MASKMAP_IDX
 #undef ADD_IDX
 #undef _NORMALMAP_IDX
 #undef _NORMALMAP_TANGENT_SPACE_IDX
-#undef _THICKNESSMAP_IDX
 #undef _MASKMAP_IDX
 #undef _BENTNORMALMAP_IDX
 
 #ifdef _NORMALMAP_TANGENT_SPACE2
 #define _NORMALMAP_TANGENT_SPACE_IDX
 #endif
-#ifdef _THICKNESSMAP2
-#define _THICKNESSMAP_IDX
-#endif
 #ifdef _MASKMAP2
 #define _MASKMAP_IDX
 #endif
 #undef ADD_IDX
 #undef _NORMALMAP_IDX
 #undef _NORMALMAP_TANGENT_SPACE_IDX
-#undef _THICKNESSMAP_IDX
 #undef _MASKMAP_IDX
 #undef _BENTNORMALMAP_IDX
 
 #ifdef _NORMALMAP_TANGENT_SPACE3
 #define _NORMALMAP_TANGENT_SPACE_IDX
 #endif
-#ifdef _THICKNESSMAP3
-#define _THICKNESSMAP_IDX
-#endif
 #ifdef _MASKMAP3
 #define _MASKMAP_IDX
 #endif
 #undef ADD_IDX
 #undef _NORMALMAP_IDX
 #undef _NORMALMAP_TANGENT_SPACE_IDX
-#undef _THICKNESSMAP_IDX
 #undef _MASKMAP_IDX
 #undef _BENTNORMALMAP_IDX
 
     surfaceData.metallic = SURFACEDATA_BLEND_SCALAR(surfaceData, metallic, weights);
     surfaceData.tangentWS = normalize(input.worldToTangent[0].xyz); // The tangent is not normalize in worldToTangent for mikkt. Tag: SURFACE_GRADIENT
     surfaceData.subsurfaceMask = 0;
-    surfaceData.thickness = SURFACEDATA_BLEND_SCALAR(surfaceData, thickness, weights);
+    surfaceData.thickness = 1;
     surfaceData.diffusionProfile = SURFACEDATA_BLEND_DIFFUSION_PROFILE(surfaceData, diffusionProfile, weights);
 
     surfaceData.materialFeatures = MATERIALFEATUREFLAGS_LIT_STANDARD;