Recreate UVs Using XYZ Coords
From Nevercenter 3D Modeling Wiki
Default Shortcut: Ctrl + U
Menu Path: UVs/Materials > Recreate UVs > Using XYZ Coords
Description
Recreates selected UVs using the corresponding vertex positions on the object. Since this method is the default for newly created shapes, applying this comand is also like "resetting" the UVs.
Notes
- This command can be applied to component selections (such as selected faces) if you only want to recreate UVs for part of the object.