[Design Task, code is not final]
This is an attempt to add the new cursor and spherical falloff to Texture Paint, to match the behavior of the brushes and cursor of Sculpt Mode/Sculpt Vertex Colors.
I would say that this is the behavior most people expect from the default texture paint brushes. If we are going to merge UDIM texture painting in 2.82, it may be a good idea to have this and the brush parameters in D5697 working to avoid users running into the most obvious and anoying limitations of the system while trying UDIM painting for the first time.
This quick implementation is hacked on top of the UDIMs patch D3509. Painting with normal falloff, occlude and backface culling works, but:
- It produces artifacts at the seams
- Symmetry does not work
- It still uses screen space units in a lot of places, so there may be other artifacts related to that.
- It needs world spacing (like sculpt mode, can be easily enabled).
I've never worked with the texture paint projection code, so I don't have a global vision of the system. Is this approach valid or does it have other kinds of limitations/issues that cannot be fixed without bigger changes?