Matte
A merge operation that layers premultiplied foreground over background.
Parameter Types
Parameter descriptions
ForegroundThe
color4foreground input.Frepresents the RGB component of this parameter.frepresents the alpha component of this parameter.BackgroundThe
color4background input.Brepresents the RGB component of this parameter.brepresents the alpha component of this parameter.MixThe weight of the blend operation. The higher the value of
Mix, the more apparent the effect of the blend operation. The default value is1. Values outside of the range0-1produce an undefined effect outside of the node’s intended function.
Discussion
The Matte node determines its output using the alpha channels of the foreground and background inputs. The RGB component of the output is Ff+B(1-f) and the alpha component of the output is f+b(1-f). Below is a simple node graph that uses the In 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]