Fix POM tiling issues (height, shadows)

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

 #if defined(_HEIGHTMAP)
     maxDisplacement = _HeightAmplitude;
 #endif
-    // TODO: explain this 0.5 factor. It is likely related to the fact that
-    // setting the amplitude to 2 in the UI only results in the max. displacement of 1.
-    return 0.5 * maxDisplacement;
+    return maxDisplacement;
 }
 
 // Return the minimun uv size for all layers including triplanar
         // Since POM "pushes" geometry inwards (rather than extrude it), { height = height - 1 }.
         // Since the result is used as a 'depthOffsetVS', it needs to be positive, so we flip the sign.
         float verticalDisplacement = maxHeight - height * maxHeight;
-        return verticalDisplacement / NdotV;
+        // IDEA: precompute the tiling scale? MOV-MUL vs MOV-MOV-MAX-RCP-MUL.
+        float tilingScale = rcp(max(_BaseColorMap_ST.x, _BaseColorMap_ST.y));
+        return tilingScale * verticalDisplacement / NdotV;
     }
 
     return 0.0;
     float height = (SAMPLE_UVMAPPING_TEXTURE2D_LOD(_HeightMap, sampler_HeightMap, layerTexCoord.base, lod).r - _HeightCenter) * _HeightAmplitude;
     #ifdef _TESSELLATION_TILING_SCALE
     // When we change the tiling, we have want to conserve the ratio with the displacement (and this is consistent with per pixel displacement)
-    height /= max(_BaseColorMap_ST.x, _BaseColorMap_ST.y);
+    // IDEA: precompute the tiling scale? MOV-MUL vs MOV-MOV-MAX-RCP-MUL.
+    float tilingScale = rcp(max(_BaseColorMap_ST.x, _BaseColorMap_ST.y));
+    height *= tilingScale;
     #endif
     return height;
 }
         // Since POM "pushes" geometry inwards (rather than extrude it), { height = height - 1 }.
         // Since the result is used as a 'depthOffsetVS', it needs to be positive, so we flip the sign.
         float verticalDisplacement = maxHeight - height * maxHeight;
-        return verticalDisplacement / NdotV;
+        // IDEA: precompute the tiling scale? MOV-MUL vs MOV-MOV-MAX-RCP-MUL.
+        float tilingScale = rcp(max(_BaseColorMap_ST.x, _BaseColorMap_ST.y));
+        return tilingScale * verticalDisplacement / NdotV;
     }
 
     return 0.0;

Assets/ScriptableRenderPipeline/ShaderLibrary/PerPixelDisplacement.hlsl

 // ref: https://www.gamedev.net/resources/_/technical/graphics-programming-and-theory/a-closer-look-at-parallax-occlusion-mapping-r3262
 float2 ParallaxOcclusionMapping(float lod, float lodThreshold, int numSteps, float3 viewDirTS, float maxHeight, PerPixelHeightDisplacementParam ppdParam, out float outHeight)
 {
-    // TEMP: 1/5 to achieve parity between tessellation and POM w.r.t. height for a single tile.
-    // TODO: explain this factor. Is there a connection with the number of samples?
-    maxHeight *= 0.2;
+    // TODO: explain this factor! Necessary to achieve parity between tessellation and POM w.r.t. height.
+    maxHeight *= 0.1;
 
     // Convention: 1.0 is top, 0.0 is bottom - POM is always inward, no extrusion
     float stepSize = 1.0 / (float)numSteps;