Texture Mapping

Not only can textures affect the color of a material, they can also affect many of the other properties of a material. The different aspects of a material that a texture influences are controlled in the Influence panel.

Surface and Wire

Texture Influence panel for a Surface material

Texture options for Surface and Wire materials and in some cases also for Volume and Halo materials.

Diffuse

Intensity: Amount texture affects affects diffuse reflectivity
Color: Amount texture affect the basic color or RGB value of the material
Alpha: Influences the opacity of the material. See Use Alpha for Object Transparency. Also use Z Transparency for light and if combining multiple channels.
Translucency: Influences the Translucency amount.

Specular

Intensity: Amount texture affect specular reflectivity
Color: Influences the Specular color, the color of the reflections created by the lamps on a glossy material.
Hardness: Influences the specular hardness amount. A DVar of 1 is equivalent to a Hardness of 130, a DVar of 0.5 is equivalent to a Hardness of 65.

Shading

Ambient: Influences the amount of Ambient light the material receives.
Emit: Influences the amount of light Emitted by the material.
Mirror: Influences the mirror color. This works with environment maps and raytraced reflection.
Ray Mirror: Influences the strength of raytraced mirror reflection.

Geometry

Normal: Commonly called bump mapping, this alters the direction of the surface normal. This is used to fake surface imperfections or unevenness via bump mapping, or to create reliefs.
Warp: Warp allows textures to influence/distort the texture coordinates of a next texture channel. The distortion remains active over all subsequent channels, until a new Warp has been set. Setting the factor at zero cancels out the effect.
Displace: Influences the Displacement of vertices, for using Displacement Maps.

Blending

Blend: How this channel interacts with other channels below it. See Compositing Mix Node for information and examples on the effect of each mixing mode.
RGB to intensity: With this option, an RGB texture (affects color) is used as an intensity texture (affects a value).
Blend Color: If the texture is mapped to Col, what color is blended in according to the intensity of the texture? Click on the swatch or set the RGB sliders.
Negative: The effect of the Texture is negated. Normally white means on, black means off, Negative reverses that.
Stencil: The active texture is used as a mask for all following textures. This is useful for semitransparent textures and "Dirt Maps". Black sets the pixel to "untexturable". The Stencil mode works similar to a layer mask in a 2D program. The effect of a stencil texture can not be overridden, only extended. You need an intensity map as input.
DVar: Destination Value (not for RGB). The value with which the Intensity texture blends with the current value. Two examples:

The Emit value is normally 0. With a texture mapped to Emit you will get maximal effect, because DVar is 1 by default. If you set DVar to 0 no texture will have any effect.
If you want transparent material, and use a texture mapped to Alpha, nothing happens with the default settings, because the Alpha value in the Material panel is 1. So you have to set DVar to 0 to get transparent material (and of course Z Transparency also). This is a common problem for beginners. Or do it the other way round - set Alpha to 0 and leave Dvar on 1. Of course the texture is used inverted then.

Bump Mapping

Settings for bump mapping.

Method: Best Quality, Default, Compatible, Original
Space: Texture Space, Object Space, View Space

Volume

Texture Influence panel for Volume material

Special texture options for Volume materials

Density: Causes the texture to affect the volume's density.
Emission: Causes the texture to affect the volume's emission.
Scattering: Amount the texture affects scattering.
Reflection: Amount the texture affects brightness of out-scattered light
Emission Color: Amount the texture affects emission color.
Transmission: Amount the texture affects result color after light has been scattered/absorbed.
Reflection Color: Amount the texture affects color of out-scattered light.

Halo

Texture Influence panel for a Halo material

Special texture options for Halo materials

Size: Amount the texture affects ray mirror.
Hardness: Amount the texture affects hardness.
Add: Amount the texture affects translucency.

Doc:2.6/Manual/Textures/Options/Map Input