Contents

Over

A merge operation that layers foreground over background, using the alpha of the foreground.

Parameter Types

Parameter descriptions

Foreground

The color4 foreground input. F represents the RGB component of this parameter. f represents the alpha component of this parameter.

Background

The color4 background input. B represents the RGB component of this parameter. brepresents the alpha component of this parameter.

Mix

The weight of the blend operation. The higher the value of Mix, the more apparent the effect of the blend operation. The default is 1. Values outside of the range 0-1 produce an undefined effect outside of the node’s intended function.

Discussion

The Over node determines its output using the alpha channels of the foreground and background inputs. The RGB component of the output is F+B(1-f) and the alpha component of the output is f+b(1-f). The lower the alpha of the foreground, the more the background blends into the foreground. Below is a simple node graph that uses the Over node to blend a wood and rock texture:

[Image]

Below are the two original images, the image representation of the alpha of the foreground, and the resulting blended texture applied to a cube:

[Image]

See Also

Nodes