negative texture coords in wavefront obj format

OpenGL OpenGL: Basic Coding
1

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

2

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.