Wavefront OBJ

Wavefront OBJ (OBJ) is a 3D modeling format associated with Wavefront's Advanced Visualizer software, but used by other software as well, for similar uses as STL. It uses various polygons, where STL uses only triangles.

.obj files are plain text. There is also a binary formulation of the format, with extension .mod.

OBJ files may reference external "material" (.mtl) files.

Specifications

 * OBJ_SPEC.PS
 * OBJ_SPEC.TXT
 * http://www.martinreddy.net/gfx/3d/OBJ.spec

Online tools

 * Convert OBJ files to STL files

Sample files

 * http://people.sc.fsu.edu/~jburkardt/data/obj/obj.html
 * Many 3D models are in Smithsonian set, in this and other formats

Links

 * , from the Encyclopedia of Graphics File Formats
 * Wikipedia: Wavefront .obj file
 * Wikipedia: The Advanced Visualizer
 * OBJ File Format – Simply Explained
 * STL and OBJ files 101