Garbage Mattes in SDI output

Hi,

Now with the new SDI and media features, I need to be able to render an object that is “not” shown in the FILL but it is rendered in the KEY output. Basically the object is not visible in FILL but it is in KEY.

I can’t use a masked material as I need the alpha/key to be feathered (gradient) in its borders.I have been trying with all kind of parameters in materials blueprints with no luck. If the only way would be implementing something in C++, it is definitely an option for us.

Not sure in what section I should put these, as it can be related to more than one. I apologize in advance if it should be in a different one.

Many thanks!