Glossary

scene graph

The general term for a data structure that holds the objects within a particular scene. Objects in a scene graph often have parent-child relationships for their transforms, as well as references to the shaders, meshes, and textures needed to render them.

projective texturing

A texture mapping technique that generates texture coordinates to make a 2D texture appear to have been projected onto a surface. This is done by transforming the vertex positions of objects into the scene through a projective series of transformations into the space of the texture itself.

spotlight source

A light source that emits from a position in the world in a generally conical shape along a particular direction. Some spot lights have a full orientation, while others only need a direction. Spotlights can be implemented in shader code, or more generally via projective texturing techniques.

cube map texture

A type of texture that uses 6 2D images to represent faces of a cube. It takes 3D texture coordinates that represent a direction from the center of a cube onto one of these faces. Thus, each texel on each of the 6 faces comes from a unique direction. Cube maps allow data based on directions to vary based on stored texture data.

texture compression

A set of image formats that stores texel data in a small format that is optimized for texture access. These formats are not as small as specialized image file formats, but they are designed for fast GPU texture fetch access, while still saving significant graphics memory.