What is UV Mapping?
UV Mapping is the 3D modelling process of making a 2D image representation of a 3D model, although it is typically used to refer to mapping textures to 3D objects. The 'u' and 'v' axes of the texture (as 'x', 'y', and 'z' are already used by the Cartesian co-ordinate system) are mapped to specific points on a 3D polygon / object. The texture is then copied across as texels, and stretched (or shrunk) to fit the polygon. UV Mapping is the typical method of textures being attached to objects in games.
What is a texel?
A texel is a texture pixel, or a texture element, analogous to a pixel. Just as pictures are in reality 2D arrays of pixels, a texture is a 2D array of texels. Texels are then mapped to pixels on screen by the GPU.
What is a texture?
A texture is an image which consists of texels. The entire purpose of textures is to add colour to what would otherwise be an entirely colourless world. Textures are stored as ordinary images (that is to say, PNGs and JPEGs), and can have transparency - however, this is handled differently by different graphics engines.
What questions does this tag cover?
This tag covers any questions which involve:
- The question involves issues with UV textures mapping to polygons.
- It is a question based upon an issue with the implementation or theory of UV Mapping.
- The question involves issues with calculating where UV co-ordinates should be mapped.
- It is a game-specific question (read the faq) - otherwise, ask it on Stack Overflow.
Different forms of UV Mapping
- The question involves topics which are closely related to UV Mapping, but are subtly different.
- This covers topics such as UVW Mapping, which is a more complex form of UV mapping.
Where can I get more information?
If you're new, then some good sites to get information from are:
- Wikipedia - as stupid as it sounds, Wikipedia explains it well, albeit with a lot of words.
- Blender Documentation - The first few paragraphs of the blender documentation here cover the basic concept of UV mapping with some good examples, and minimal reference to Blender itself.
On the other hand, if you're looking for more in-depth information:
- Ask here - after all, that is what GD.SE is about - if you have a good question, it'll get good answers.
If you're looking for a specialist topic about a subset / niche of UV mapping:
- Blender Forums - the Blender Forums are your friend. Although a question is likely to get a response involving Blender itself, the people there are willing to answer questions on niche topics to do with UV Mapping - after all, it is what they spend their time doing.