Hi Thanks for your reply. .obj is an ASCII file format, I don't think byte order would be an issue here.
On 2010-04-20, at 11:55 AM, A.M. wrote: > > On Apr 19, 2010, at 12:33 PM, Peter Willsey wrote: > >> Hello All, >> >> I've been developing a screensaver in Objective-C using OpenGL to render an >> object in wavefront .obj format. The object is displayed and rotated on the >> X, Y and Z axis. I have enabled lighting and I'm calculating surface >> normals so that shading works properly. >> >> I have been developing this plugin on a 2.4Ghz Intel Core 2 Duo Mac Book Pro >> with a GeForce 8600M GT video card with 256 MB of VRAM. Everything was >> working great until I compiled a PPC version of my screensaver and tried >> running it on my Power Mac G5 Tower with a GeForce FX 5200 video card. The >> Screensaver loads and displays, but there appears to be some issues with >> shading and lighting. As the model rotates areas of the model flash, and >> dark colors pass over top in strange patterns. From certain angles areas of >> the model almost completely disappear. >> >> Not sure if this is relevant, but I'm not using any textures in the model. >> I've also tried importing the .obj file into a 3D program and exporting it >> back into .obj format with vertex normals included in the file, and using >> those instead of calculating surface normals myself. I've tried using >> GL_FLAT and GL_SMOOTH shading models. >> >> This does not occur on my Intel machine. Both machines are running Mac OS X >> 10.5.8. I'm not sure if this is related to the video card, the driver, the >> fact that the machine is a PPC or if it's just older hardware that I should >> not try and support ? > > This is almost certainly an endianness issue. Make sure that you are reading > the correct endianness out of the file and converting it, if necessary. > > http://developer.apple.com/mac/library/documentation/Darwin/Conceptual/64bitPorting/MakingCode64-BitClean/MakingCode64-BitClean.html > > Cheers, > M _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
