# Bump Operator

The Bump Operator simulates a lit 3D surface in a texture, using the Blinn-Phong shading model.

## Inputs

Two textures: a carrier (left input) and a modulator (right input). The carrier can be any texture. For the bump to yield a meaningful result, the modulator branch should end in a Normals Operator set to 3D mode. It acts as a map for the simulated 3D structure.

## Parameters

### Mode

Defines the type of light to use.

spot: a directed light cone.

point: a single point of light emitting light in all directions equally.

directional: parallel rays from a single direction.

### Pos (X, Y, Z)

(mode: spot/point) Controls the position of the light source.

(mode: directional) No function.

### Dir (Z, X)

(mode: spot/directional) Controls light direction, expressed in rotation around Z axis and rotation around local X axis – try to imagine it as if the light was shining out of a bicycle's front wheel valve. The first value turns the handle bar, the second value turns the wheel. And the wheel is transparent and infinitely small. Sorry.

(mode: point) No function.

### Diffuse

Defines the diffuse color.

### Ambient

Defines the ambient color.

### Outer

(mode: spot) Controls light cone diameter.

(mode: point/directional) No function.

### Falloff

(mode: spot) Controls the light cone edge softness.

(mode: point/directional) No function.

### Amplify

Controls the strength of the light and shadow effects.

## Specular

Defines the specular color.

### Power (hardness)

Controls the edge definition of the specular reflection. Power 0 equals no specular.

### Amplify

Controls the amount of specular reflection.

## Keyboard shortcut

Shift + B (when adding texture operators)

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