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19.3 3D Texture Portability

With the release of OpenGL 1.2, 3D texturing is now core feature of OpenGL, but the functionality is also available via the EXT_texture3D extension. Even when 3D texture maps are supported, the application writer must be careful to consider the level of support present in the application. Texture map size may be limited, and 3D mipmapping is sometimes not supported in hardware. Available internal and external formats and types may be restricted. All of these restrictions can be queried at run time, and with care, portable code can be produced.

Consider writing your 3D texture applications so that they revert to a 2D texturing mode if 3D textures are not supported. See Section 16.2 for an example of a 3D texture algorithm that will work, with lower quality, using 2D textures.