UV map

From Valve Developer Community
(Redirected from UV)
Jump to: navigation, search

A UV map is a part of an object's geometry. It defines which areas (using UV coordinates) of a 2D pixelmap should be rendered on which polygonal surfaces (using XYZ coordinates) of a particular 3D mesh. A UV map does not contain any pixel data (eg color, etc). It is only a matrix relating 2D to 3D coordinates.

In Source, the object's UV map is stored in a VMT file and reads the pixel data from the same UV area of each VTF in the texture stack. Therefore one UV map imports data from the colormap, bumpmap, opacitymap, specularmap, etc as though they were one image (with enormous bitdepth). Thus the object's Material can easily be changed without having to rebuild the UV map.

Note.png Note: Models tend to have a more complex mesh than brushes, which makes UV mapping much more fiddly. Model VTFs therefore tend to be created specially to map easily and efficiently onto one specific model only. Models may use multiple (alternative) skins, so long as the layout of each VTF corresponds to the model's UV map.

UV Mapping, or Texture Mapping, is the process of aligning Polygons to Pixels.

See Also