- Tangent calculation functions no longer use the CustomData struct as
an input and output.
- The "orco" and UV map calculations are exposed as separate API
functions to avoid a confusing internal choice between the two
- Redundancy in the API is removed, function names are clarified
- Code is moved to C++ namespace
- The "orco" case is clarified in the mesh draw tangent VBO extraction
- CD_TANGENT layers are not stored in CustomData anymore, so some of
that infrastructure is removed.
- Broken logic for caching tangents in CustomData is removed. That
hasn't worked for many years, if it every worked. We could investigate
adding caching again later if that's helpful.
Overall the change is motivated by the need to move away from CustomData
for #122398. But the changes should be a general improvement that makes
the code easier to understand either way.
Testing for this PR included using the default render UV in materials,
referencing specific UV tangents by name, using the spherical position-
based tangents in a material, and baking textures (multires and normal
baking).
Pull Request: https://projects.blender.org/blender/blender/pulls/141799
b19696c0b8