Bringing depth and structure to a texture can be achieved with the Bump functions. Different illumination and shadow casting techniques combine the texture with a Heightmap, which supplies the depth data.

The Bump functions:

	Cast Shadows	Darken unlighted areas.
	Diffuse	Combine transformed diffuse and ambient light.
	Emboss	Simple directional embossing.
	Fast Shader	Fast standard dot3 bumpmapping.
	Homogeneous Light	The opposite to the cast shadows function.
	Point Light	A radial light source at the center.
	Quad Light	Four light sources at the corners.
	Sharp Emboss	Single colored simple embossing.
	Variate	Slight structurizing effects.