In computer graphics, clipmapping is a method of clipping a mipmap to a subset of data pertinent to the geometry being displayed.
It is also featured in Splash Damage's game Enemy Territory: Quake Wars, and was developed by id Software former technical director John Carmack.
Depending on the pixel resolution per square meter, covering a large area could require several gigabytes of memory.
However, RAM is also filled by the rest of the game and the underlying operating system, limiting the amount available for texturing.
The goal being to be able to stream parts of the octree into video memory, going further down along the tree for nearby objects to give them more details, and to use higher level, larger voxels for farther objects, which give an automatic level of detail (LOD) system for both geometry and textures at the same time.