1. Does not work on current beta build (invisible). Can be fixed with new Lighting.glsl shader which was not yet added to build.
2. On one side normal looks correct like scratch and on other like "vein":
3. If surface have normal map, decal looks wrong by having different color and visible borders. Most likely it's happens due full "rewrite" of surface normal map.
Can be decal normal map be just "above" or something like that to prevent it?
Map, mats, shader:
DecalNormals.zip