Texture atlas

In realtime computer graphics, a texture atlas (also called a sprite sheet or an image sprite) is an image containing a collection of smaller images, usually packed together to reduce the atlas size. Atlases can consist of uniformly-sized sub-images, or they can consist of images of varying dimensions. A sub-image is drawn using custom texture coordinates to pick it out of the atlas. In an application where many small textures are used frequently, it is often more efficient to store the textures in a texture atlas which is treated as a single unit by the graphics hardware. Storing textures in an atlas reduces the overhead of a context switch by increasing memory locality. Careful alignment may be needed to avoid bleeding between sub textures when used with mipmapping and texture compression.

Gallery

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  A texture atlas for a video game

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  A texture atlas of glyphs

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  Sprite sheet for the video game Blades of Exile

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  A human model and "skin" from the MakeHuman project, as viewed in the program, Blender

External links

Explanations and algorithms

• Texture Atlas Whitepaper - A whitepaper by NVIDIA which explains the technique.
• Practical Texture Atlases - A guide on using a texture atlas (and the pros and cons).
• A thousand ways to pack the bin - Review and benchmark of the different packing algorithms
• Sprite Sheets - Essential Facts Every Game Developer Should Know - Funny video explaining the benefits of using sprite sheets

Tools

• TexturePacker - sprite sheet packer with graphical user interface and tons of options. Works with almost all game engines.
• LibGDX texture packer - Open source texture packer utility from libGDX
• Texture Atlas Maker - Open source texture atlas utility for 2D OpenGL games.
• SpriteMapper - Open source texture atlas (sprite map) utility including an Apache Ant task.