Substance painter file format support

This is a small thing, not required but the reason why a lot of my friends end up not using this software is because it doesn't work with their existing substance painter files. Is there any way that format could be implemented?

The issue names no file, test, or importer entry point. First identify how ArmorPaint currently handles project and file formats, then determine the scope of Substance Painter compatibility. Done means the supported Substance Painter files import reliably and the expected compatibility is documented and tested.

Written by the indexing model from the issue text.