Texture maps can be used to significantly enhance the appearance of surface, giving surfaces a realistic appearance without adding large amounts of geometric detail.

Example scene without textures:

Same scene with textures applied:

Textures can be applied to surfaces in a great variety of ways.

The image used as a texture map should be of high quality to give a good surface effect, but while it is acceptable to use high resolution texture maps for 3D modelling to create pre-rendered animations, great care should be taken to restrict the size of the texture maps so as not to use up all of the graphic card's texture memory. Most modern graphics cards now have 16 to 32Mb of texture memory, while laptop computers often have only 4 or 8Mb available.

The most common way to make "realistic" texture maps is now to use a digital camera to photograph a surface and the manipulate the image in a package like Adobe Photoshop. Packages such as Photoshop also have filters that can be used to create entirely artificial (computer generated) images that can also be used as texture maps.

Projection methods

Textures can be projected onto surfaces using planar, cylindrical, or spherical projection mapping, depending on the desired effect. These are very simple methods of projection but are quite limited (e.g. a planar projection on a cube will have one side mapped with the texture while the other sides show the texture streaked).

Parameterised texture mapping

Another form of texture mapping (which avoids the streak effect of the projection methods)is parameterised texture mapping which is more like taking an image and stretching it all the way across the outer side of a surface.

Texture mapping parameters

Most 3D packages offer a number of parameters that can be set to control texture mapping:

• Scale
• Placement
• Wrapping

Used in combination, a great deal of control over the texture is available.

Bump and displacement maps

In some 3D systems, textures can also be used to define bump maps or displacement maps. Bump maps simulate small irregularieties in a surface without altering its geometry whereas a displacement map actually alters the geometry of the mapped surface. Displacement maps can be used to model the sea or hilly terrain.