OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

Cube-Map Textures

Cube-map textures are a special type of texture, useful for environment mapping, that takes a set of images and treats them as the faces of a cube. The six faces of the cube are represented by six subtextures that must be square and of the same size. When you sample from a cube map, the texture coordinate used is three dimensional and is treated as a direction from the origin. This direction essentially points at the location on the surface of the cube from where to read the texture. Imagine you were standing in the middle of a square room with a laser pointer. You could point the laser in any direction and hit part of the wall, floor, or ceiling of the room. The spot where the pointer shines is the point from which you would ...