Placing a black mask over images in Isadora Core

[ursullivision]

I haven't been able to figure out how to create a simple black mask over Multiple CI Projectors which are being used to composite alpha channeled video.  I've been using Mark's CI Classic Crop actor as the last actor infront of each CI Projector, but I lose the alpha channel of my image when I pass it through the CI Classic Crop Actor.

I'd ideally like to be able to use a CI projector, put it on the highest layer, and use a black and white rectangle to crop the image using the blend modes.  So far it only works with a white mask (Black=transparent, so I can't get a black mask).  I'm sure I'm missing a very simple concept here.  Any ideas?

Thanks in advance,

ur,ummmm......................................Eric

EDIT:

I figured it out...You have to use the projectors to make the masks by sending CI constant color (Black) to the projector, and then by sizing the crop in the projector itself.