System Information
Operating system: macOS Big Sur 11.5.2
Graphics card: Apple M1
Blender Version
Broken: 2.93 and 3.0 Alpha
Short description of error
Using the collection info node in geometry nodes destroys custom normals data when the geometry node modifier is applied (or when the project is exported).
Exact steps for others to reproduce the error
Apply the geometry node modifier on the "Dummy" object in the attached blender project. I've also included a video that shows the issue.
A bit will survive as attributes (but not really usable as-is):
@Jacques Lucke (JacquesLucke) : @Hans Goudey (HooglyBoogly) : this would also be the same ballpark as T89054: Improve integration of generic attributes?
(though normals are not even stored into attributes...)
Yeah, we haven't looked into supporting custom normals in geometry nodes yet. They should be a vector attribute on the face corner domain, editable just like any other attribute. But I wouldn't expect it to work until then.
Until we decide how to handle custom normal data in geometry nodes, this situation is unlikely to change.
Theoretically it might not be complicated-- there could be a "Set Custom Normals' node that evaluates a vector field on the face corner domain. But that may require other changes or more design thought.
Sure. I find it a bit confusing though, that the normals are only destroyed the moment the geometry nodes modifier is baked down when hitting apply. If geometry nodes can't handle custom normals the logical thing would be to remove the custom normals as soon as the modifier is added to the object. Currently, the modifier behaves differently when it is applied (compared to how it works when it is attached) which feels buggy.