Creative Effects > Modular Keyer > Using Blend Nodes >
Matte Blend Node

Use the MBlend node to set up the matte operations you want to perform on a clip.

Use the Front pipe of a layer to define the matte, and use the Matte pipe to isolate an area where you want the matte to be applied. For example, use the Matte pipe to isolate an area of the key-in clip and apply a different matte to that area.

NoteWhen using the Matte pipe for this purpose, you would create a second layer and place the overall matte in the bottom layer and the second, localized matte in the upper layer. This is because layers are processed from the bottom up. See Using Several Layers in a Blend Node.

When there are no nodes on the Matte pipe, the matte is applied to the entire image.

As with the CBlend node, you can blend the front and back images for each layer and create several layers of mattes.

How the MBlend Node Works

The Front and Matte pipes of the MBlend node are both designed to result in a matte. This is represented visually by a blue box at the right of the Front and Matte pipes. You can place any node on the Front and Matte pipes that results in a matte, including the 3D Keyer, MasterK, 2D Histogram, GMask, Edge and Degrain nodes.

NoteThe Degrain node results in a colour image; however, it is often useful to place it on the Matte pipe before the Keyer-3D node (which uses a colour image for its input). For this reason, it can be placed on the Matte pipe. (In Flint, place the Degrain node before the MasterK node.)

The Front and Matte pipes of the MBlend node constitute one layer.

(a) One layer(b) Front pipe(c) Matte pipe(d) Blue box of Front pipe(e) Blue box of Matte pipe

The two pipes together, along with a back component, constitute one layer. For the first (bottom) layer, the MBlend node uses a pure black image for the back component. To learn how subsequent layers are composited, see Using Several Layers in a Blend Node.