Is there a way to extract the mapping color area of the mesh?

hello!
I’m here to ask for your help because there’s something I can’t solve.

Is there a way to extract the mapping color area of the mesh?
I want to create a boundary curve of the black area.

(The mesh itself has no color, but only the mapping file has color.)

Thank you for reading.
I’ll be waiting for help!


test1.3dm (3.7 MB)