This is a post by Aaron Shaw on PTC site.
Need to work with geometry created in other applications? We’ve added geometry in Freestyle to our import and export support. Here’s what you need to know to get started using it:
Import a Mesh
You can import a Wavefront OBJ file that was created in any application. With this open format, you can share simple data, including vertex positions, normal, and faces—all of which can be edited in Creo. Just follow these steps: