Texels

Texels and Textures

After the programmer/artist creates the 3D object he has to paint the polygons with an image. It's texel time! A texel, short for texture element, is an individual pixel that is part of a larger bit-mapped image called a texture. A texture can represent almost anything from water to a brick wall. Programmers apply textures to polygons to make 3D objects more realistic. A programmer might apply a wood texture to a cube to create a simple wooden crate. This particular texture is from Quake III. Obviously, it's dirt. You can make a dirt floor that is bumpy by wrapping this texture on the surface of a polygon that makes up part of the ground.

Once you get really close to a textured object it'll appear blocky, and you'll start seeing the individual texels become jagged along the edges as the textures from both polygons begin to fight over the pixel space along the edge. There are various filtering techniques like bilinear, trilinear, and anisotropic filtering to smooth out rebelling pixels.

Because of hardware limitations, most textures used in today's games are pretty small -less than 256 x 256 pixels in size. We'll see larger, more realistic textures once video cards begin supporting larger texture sizes. S3's texture compression technology (S3TC) gives gamers a small taste of the future. S3TC's 6:1 compression technology expands texture storage capacity sixfold, allowing for huge photorealistic textures. Epic games already has a special large texture version of Unreal that takes advantage of S3TC technology.

Here are a couple more textures from Quake III. These textures are 128 x 128 big, while the bottom one is 256 x 256 big.

;