Creo

A PRT file is a part file created by PTC Creo Parametric, a CAD program part of the Creo suite that is used to design manufactured parts and assembly processes. It contains part information, including a 3D model and part structure. PRT files can be combined with other parts into an assembly file (.ASM file).

Read more

OBJ

OBJ (or .OBJ) is a geometry definition file format first developed by Wavefront Technologies for its Advanced Visualizer animation package. The file has been adopted by many 3D graphics application vendors.

The OBJ file format is a simple data-format that represents 3D geometry alone — namely, the position of each vertex, the UV position of each texture coordinate vertex, vertex normals, and the faces that make each polygon defined as a list of vertices, and texture vertices. Vertices are stored in a counter-clockwise order by default, making explicit declaration of face normals unnecessary. OBJ coordinates have no units, but OBJ files can contain scale information in a human readable comment line.

Read more