Hi, I'm trying to design my own 3d engine with cubic beziers patches being the primary primative (as opposed to dealing directly with triangles) and I'm pretty familiar with techniques like forward dfferencing to render the patches. My problem is importing geometry from standard file formats like .OBJ (.OBJ is one of a number of formats, but it seemed like the easiest and most common to start with). I've read the file format specifications that are posted on www.wotsit.org but most modelling programs store all curves as complex curves rather than nicely defined control points. What I would like to know is how to take that info out of the file and derive the control points from it and, in the case of more complex curved surfaces, how to break the curves up into smaller cubic patches. If anyone knows how to do this, knows of an example/tutorial, or knows of another file format that is easier for this please let me know. Any help would be greatly appreciated. -Daedalus Edited by - Daedalus on 2/6/00 5:53:40 PM Edited by - Daedalus on 2/6/00 5:54:24 PM