The reference I have states: "Each element references the vertices stored immediately above it in the file." As the only file I've with minus indeces in it is this one, and the preceeding 4 lines are vts, don't know what else I can infer from that! The file I'm reading "obj_spec.pdf" doesn't seem to be copyrighted in any way, so I can mail it to you if you want. It probably came from Wotsit.org, that's where I get most such stuff, it might be worth searching there for something more up to date. John PS of course the order doesn't have to be inversed, it would depend on the face normal.