Geometry Nodes can change the materials of the Object, for Mesh Objects,
the new materials are present in the evaluated Object, but for non-Mesh
Objects, the new materials may not be present until the evaluated Object
has been converted to a Mesh.
This patch fixes the materials in FBX export, with Apply Modifiers
enabled, of non-Mesh types with Geometry Nodes that change materials.
Rather than getting the materials from the evaluated Object, the
materials are now retrieved from the Mesh created from the evaluated
Object.
To support object-linked material slots, the materials on the new Mesh
are replaced at the same indices as the object-linked material slots.
Pull Request: https://projects.blender.org/blender/blender/pulls/130485
Thomas Barlow
8ed98d592e