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Well, I've got many UV coordinates of a 3D model clearly in the range 0-1 and many coords in seemingly pixel values in the range 100-300.

How do I know which one to interpret the coordinates as? Is there a standard or system for this?

I notice that each 3d meshes in the exported file may use either system. Is this normal procedure, and if so, how do I interpret the UV texture mapping coordinates to display them correctly in my 3d engine?

Examples of coordinates in the 0-1 system:

vt 1.04017 2.60853

vt -0.984585 -0.0106576

Examples of coordinates measuring by the pixel:

vt -208.397 776.637

vt -208.397 32.6369
Robin Rodricks
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1 Answers1

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What is the file format of your 3D model? Also note that it's perfectly valid to have UV mapping coordinates ranging outside 0-1, e.g. for wrap or repeat texturing modes (refer to OpenGL or Direct3D texturing mode).

elmattic
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  • Its an OBJ from an online 3D library. I've uploaded the model I'm using to test here. http://www.box.net/shared/s35azk05eg - Its a building, and you can see some faces apparently measured in pixels, and some in the range of -5 to 5 with great accuracy. Any help would be greatly appreciated. – Robin Rodricks Sep 17 '10 at 16:30
  • Also if your using OpenGL `GL_ARB_texture_rectangle` extension, uv coordinates need to be specified in pixels. – elmattic Feb 29 '12 at 09:54