Ex_mipmap.png|Mipmap of the Supermarket 2 floor. Bmq regions.png|Mipmap regions (yellow). Basically, a mipmap is a lower-resolution (half-sized) copy of the main texture and are used both to improve the game performance and smooth the textures. In Re-Volt, mipmaps are single bitmap files that have their extansion renamed to BMQ, and can be opened with any image editor, including Microsoft Paint. The guess is that the "Q" stands for "quick".