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View Full Version : negative texture coords in wavefront obj format



kamimail
12-12-2009, 08:16 PM
i have a building model file in which the range of texture coordinate is beyond the normal interval[0,1].
the following is the snippet from the file
.....
vt 1.389823 0.967871 -0.212541
vt 1.123831 -0.685677 -0.123045

the textures in each facet of the building is stored in one tga file.

how to render texture of the building model correctly using the opengl? thanks

Ilian Dinev
12-12-2009, 10:50 PM
Notice there are 3 dimensions. This is UVW, from 3DSmax
http://en.wikipedia.org/wiki/UVW_mapping
Just ignore the W.
Also, [0;1] is not the limit. When using a texture with repeat-wrap mode, it's common to have coords outside [0;1] - to do tiling.