Texture mapping is a method of adding detailed colour to a computer-generated graphic. An image (the texture) is added (mapped) to a simpler shape that is generated in the scene, like a decal pasted onto its surface. This allows a complicated colouring of the surface without requiring additional polygons to represent minute details.

Multitexturing is the use of more than one texture at a time on a shape. This has various uses, sometimes as a way of applying a light map to a surface, which is faster than requiring the graphics hardware to do lighting calculation for that surface on the fly, or more recently bump mapping has become popular, which allows a texture to directly control the lighting calculations, allowing the surface to not only have detailed colouring, but detailed contours as well (bumps).

The way the resulting pixels on the screen are calculated from the texels (texture pixels) is governed by texture filtering. The fastest method is to use the nearest neighbour interpolation, but bilinear interpolation is commonly chosen as good tradeoff between speed and accuracy.

At the hardware level usually texture coordinates are specified at each vertex of a given triangle (any polygon may be broken down into triangles for rendering), and these coordinates are interpolated as part of a calculation that is an extension of Bresenham's line algorithm. Direct interpolation of the texture coordinates between vertices results in affine texture mapping, which causes a percievable discontinuity between adjacent triangles when the 3D geometry of the specified triangle is at an angle to the plane of the screen, perspective correction is thus preferred where realism is important, and adjusts the texture coordinate interpolation as a function of the 3D depth of each pixel. Because perspective correction involves more calculation, it did not become commonplace in graphics hardware until recently.

See also

• Edwin Catmull
• Texture filtering
• Texture Splatting - a techique for combining textures.

External links

• Graphics for the Masses by Paul Rademacher
• High resolution textures resource
• High resolution images and textures resource
• Texture Hound | Ultimate 3d Texture Links Directory

Computer graphics | 3D computer graphics

Texturování | Texture Mapping | Texture (image de synthèse) | Texture | Textur (datorgrafik) | 纹理映射