Nodes With a Visible Matte Port

T-COMP2-002-001A

In this topic, you will learn about nodes with multiple ports. The left image port is generally used for a matte input.

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  • MO-COMP2-002/Compositing_Mattes_B

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Some effects need to be linked to another layer, referred to as a matte layer, which is used to define the area they should affect. A good example of this is the Tone effect, which is used to add a shadow of a given shape to a layer. Alone, the Tone effect has no impact on the drawing it is connected to. Once combined with a matte layer, the Tone effect will use the matte's shape to apply a shadow to the drawing. Even if the matte's shape bleeds outside of the drawing's outlines, the shadow will only be applied within the drawing's outlines.

A matte layer is simply a regular drawing layer that is connected to an effect as its matte. The effect takes the shape of the drawing in the matte layer to determine the area of the drawing it affects. The colours and details in the matte layer are ignored by the effect, only its shape is taken in account.

In the Node view, an effect must be connected to the drawing or composite it is meant to affect by its input (top) port, and its output (bottom) port must be connected to the scene's main composite.

If the effect can use a matte layer, it will have a matte port on its left to which the matte layer can be connected.

The matte port has a Matte icon underneath it. You can invert the matte by double-clicking on this icon, which will make the effect use the negative space of the matte drawing rather than the matte drawing itself as its matte. When an effect's matte is inverted, the Matte appears black on white instead of white on black: .

Once your effect is connected, you can adjust its parameters by selecting it, then adjusting its parameters using the Layer Properties view. You can also click on a node's Layer Properties icon to open its layer properties in a dialog. If desired, you can even animate the parameters of your effect by converting their values to functions.

TIP: If you need to use the uncut version of your drawing layer anywhere else in your scene, you can bypass the effect it is connected to by connecting the drawing layer's output port to other input ports of your composite, or to other effects or composite, as needed. This will create new cables, leaving your layer's connection to its effect unaffected.

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