Cube Mapping - Advantages

Advantages

Cube mapping is preferred over other methods of environment mapping because of its relative simplicity. Also, cube mapping produces results that are similar to those obtained by ray tracing, but is much more computationally efficient – the moderate reduction in quality is compensated for by large gains in efficiency.

Predating cube mapping, sphere mapping has many inherent flaws that made it impractical for most applications. Sphere mapping is view dependent meaning that a different texture is necessary for each viewpoint. Therefore, in applications where the viewpoint is mobile, it would be necessary to dynamically generate a new sphere mapping for each new viewpoint (or, to pre-generate a mapping for every viewpoint). Also, a texture mapped onto a sphere's surface must be stretched and compressed, and warping and distortion (particularly along the edge of the sphere) are a direct consequence of this. Although these image flaws can be reduced using certain tricks and techniques like “pre-stretching”, this just adds another layer of complexity to sphere mapping.

Paraboloid mapping provides some improvement on the limitations of sphere mapping, however it requires two rendering passes in addition to special image warping operations and more involved computation.

Conversely, cube mapping requires only a single render pass, and due to its simple nature, is very easy for developers to comprehend and generate. Also, cube mapping uses the entire resolution of the texture image, compared to sphere and paraboloid mappings, which also allows it to use lower resolution images to achieve the same quality. Although handling the seams of the cube map is a problem, algorithms have been developed to handle seam behavior and result in a seamless reflection.