T

tessellation

Reduction of a portion of an analytic surface to a mesh of polygons, or of a portion of an analytic curve to a sequence of lines.

texel

A texture element. A texel is obtained from texture memory and represents the color of the texture to be applied to a corresponding fragment. See also fragment.

texture

A one- or two-dimensional image used to modify the color of fragments produced by rasterization. See also rasterize.

texture mapping

The process of applying an image (the texture) to a primitive. Texture mapping is often used to add realism to a scene. For example, you could apply a picture of a building facade to a polygon representing a wall. See also texture.

texture matrix

The 4x4 matrix that transforms texture coordinates from the coordinates that they're specified in to the coordinates that are used for interpolation and texture lookup.

transformation

A warping of space. In OpenGL, transformations are limited to projective transformations that include anything that can be represented by a 4x4 matrix. Such transformations include rotations, translations, (nonuniform) scalings along the coordinate axes, perspective transformations, and combinations of these.

triangle

A polygon with three edges. Triangles are always convex.