Added support for emissiveColor in UsdPreviewSurface export, mapping the PrincipledShader's Emission input to it. Co-authored-by: pwflocal <drwave@apple.com> Pull Request: https://projects.blender.org/blender/blender/pulls/107947 A similar solution was also proposed and discussed in pull request https://projects.blender.org/blender/blender/pulls/104490 by Ashley Ruglys <ashley.ruglys@gmail.com>.