> > > Ok, I can see we have an issue with singularities, but using > mikktspace does not seem ideal for anisotropic shading. There's still > many cases where you can line up the tangents quite well at UV seams > even if the UV's are not connected,
Generally this is not the case. It goes bad at least 95% or more of all cases where you try to just average tangents from an unwrap no matter what. Borders are splits when tangents aren't aligned so odds of this going well are close to non. results if you average with two neighboring triangles, but not the > ones on the other side. > That's not what happens though. What happens is that all the tangents surrounding the pole get added together. What you end up doing is stretching the highlight in a very distorted way across the entire top row of triangles. > As I understand it mikktspace is based on comparing UV coordinates, > whereas we should actually be deciding merge/nomerge based on the > difference between tangents in UV space, with some threshold. If you were to try and achieve normal mapping using this approach then I can confidently tell you it's an awful solution. The idea has been tried and done to death by many of us game developers back in the day when the concepts of tangent space were still young. My recommendation is definitely that you use mikktspace for normal mapping. You use it for aniso as well if someone wants to use unwrap based tangents. And if someone wants to use orco then you synthesize the tangents. It's the only proper/stable/good way to do it. M.Fox. spend years on aniso in blender, studying various cases, and I am sure he can tell you first hand the per vertex averaged triangles just didn't work well. He was getting errors all the time. _______________________________________________ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers