Generated tangent has same direction as normal about mikktspace HOT 3 OPEN

I have realized that I need better texture coordinates. Most likely this should solve the issue.

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Sorry for the late response but I saw that you realized your issue. Indeed your UVs need to span an area.
Also are you using authored UVs or projected UVs? Projected UVs generally works very poorly at vertex level.

morten

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Initially I used projected (spherical) UVs and indeed that did not work well.

I improved my cylinder primitive to generate proper texture coordinates for bases as well, but then I realized I can easily generate tangents directly as well. I still had other primitives, platonic solids for example, which did not have texture coordinates nor tangents. I ended up calculating per polygon projected texture coordinates like this:

I know I probably could easily calculate tangents for these without going through texture coordinates. I still wanted to see how MikkTSpace handled these, as it is good to know if there is something that I can use as a generic solution. Then I noticed that only trinagles and quads are supported. So I virtually triangulated faces with centroid triangle fan. With that in place, I got this:

I don't have visualization for the virtual triangulation, but centroids are shown. There are now valid tangents everywhere, however, triangles in each face don't always agree on the tangent. Is this expected result?

I added post processing to pick a tangent that appears at least twice:

Would it be possible to extent MikkTSpace to natively support faces with more than 4 corners?

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