I am trying to blend two world space normals inside a shader. One comes from a tangent space normal map converted into world space using a classic TBN matrix and the other one is a mesh normal map in world space.
I found some interesting resources here :
But those blending technics seem to be only available for tangent space normals, especially the Reoriented Normal Mapping (RNM). I tried to apply the RNM technic with unpack already done.
n1 += vec3(0, 0, 1); n2 *= vec3(-1, -1, 1); return n1 * dot(n1, n2) / n1.z - n2;
But this doesn't give expected results and I don't get why. Is there a way to apply the RNM blending on world space normals ?
Thanks a lot.
Edit: Here are some output and the result I am having with RNM. The A normal is not disturbed by the B normal, it gives some strange massively reoriented results.
float3 nv = dot(normal, viewDir); color.rgb = nv;