The Inventor sheet-metal environment has been designed to work with imported geometry because its solid unfold engine is concerned with topology, not with features. This means that files imported directly from other 3D modelers such as SolidWorks, CATIA, and Pro/ENGINEER, as well as neutral file types such as STEP, SAT, and IGES files (.step, .sat, and .iges), can be brought into Inventor. Once imported, they can be modified with additional features and unfolded, provided they maintain a constant thickness that matches the thickness set in the part.
MORE ON IMPORTING PART FILES
You can find more information about importing part files and exchanging data with other CAD systems in Chapter 14.