I am having trouble using triplanar texture mapping with normal maps. I use this technique for triplanar mapping: https://www.youtube.com/watch?v=dYvh0SnAjis
I am trying to texture map asteroids so I modified it to use local coordinates instead of world coordinates by adding transforms after Absolute World Position and VertexNormalWS nodes and it seems to work well for diffuse textures. Here is my material function:
I noticed that for normal maps, half of the sides are wrong. Example:
I tried to correct this by inverting UV mapping accordingly on the opposite sides and it works for a cube. For sphere (or asteroid) it does not yield correct results all the time. If I have to guess, the problem lies in the blending of the normal maps or something to do with transforming from world to local? How can I use triplanar texture mapping with normal maps?