User Manual

Use an OFX Plug-in to Create
Transparency
If you’ve installed an OFX plug-in capable of keying, you can right-click the node you’ve applied
it to and choose Use OFX Alpha to route the key created by the plug-in out the key output of
that node. When Use OFX Alpha is enabled, the HSL Qualifier and Window palette output is
ignored, the only key that’s output is from the OFX plug-in.
Choosing Use OFX Alpha in the Node Editor
Once Use OFX Alpha is enabled, and you’ve created a key using your OFX plug-in of choice,
you can right-click anywhere within the node graph (other than on a node) and choose Add
Alpha Output from the contextual menu to make the Alpha output appear, and you can then
connect the key output from the node with the OFX plug-in to the Alpha output to use it to
create transparency.
Setting up a composite using an OFX plugin
NOTE: When Use OFX Alpha is enabled for a node, you cannot use a window to
create a garbage matte within that node as you would when keying with the HSL
Qualifier. To create a garbage matte with which to exclude unwanted and unkeyable
elements from the edges of the picture, you’ll need to combine the key from a window
in another node with the key output by the OFX plug-in using a Key Mixer node.
Chapter – 127 Channel Splitting and Image Compositing 2890