Define HoldOut Matte objects
All objects defined as “Set as hold out matte object” which are equal to the “Hold Out Matte Objects” list within the Shield Actor, are part of the seperated hold out matte render pass.
This is a simplified renderer which allowed “StaticMeshActors” with materials.
The Materials needs to be “Opaque” with a “Default Lit” shading.
The Hold Out Matte can be used to define specific parts within your green-/bluescreen to exclude these from the keyer.
This is necessary if for example parts of props within the screen has the same tint like the screen themselve.
Simply use a SDI output with this pass and connect these with your hardware keyer.
Example use of a Hold Out Matte
Let´s say this is our pure camera image
This is our background
If a keyer removed all green, we will remove the “green ball” as well
To exclude these we define a mesh or a plane object, defined as hold out matte pass
The external keyer can used these pass now to exclude these area from keying