In real-time computer graphics , a texture atlas is an image containing a set (or “ atlas ”) of sub-images, each of which is a texture for some 2D or 3D object. Sub-textures are mapped onto the object using UV conversion , while the coordinates in the atlas determine which part of the image to use. Applications often use many small textures, and switching from one texture to another is a relatively slow process. Therefore, in such situations it is advisable to use one large image instead of many small ones.
For example, in games with tile-graphics, you can get a good gain in the speed of image output.
Atlases can contain both sub-textures of the same size and sub-textures of differing sizes (usually being a power of two). To compile atlases, both generator programs and manual compilation are used. When using MIP-texturing, it is necessary to provide that the sub-textures should be arranged in such a way that there is no situation when one of them "crawls" onto the other.
See also
- Tiled rendering
- Graphics pipeline
Links
- A thousand ways to pack the bin - Review and compare the performance of various packaging algorithms.
- Sprite Sheets - Essential Facts Every Game Developer Should Know - A fun video explaining the benefits of using sprite sheets.
- Texture Atlas Whitepaper - An Explanation of Technology from NVIDIA .
- TexturePacker - Commercial program for creating texture atlases.
- Texture Atlas Maker - An open source utility for generating texture atlases for 2D OpenGL games.
- Practical Texture Atlases - A guide to using texture atlases ( pros and cons).
- SpriteMapper - A utility for creating texture atlases (sprite map) including the Apache Ant task.