render time boolean

[ficdogg]

Is there a way to make a render time boolean with corona?
I saw the distance shader for the max version and it's exactly what I was looking for, but it seems that one is not yet available for c4d.
I tried with the proximal shader but the results were not predictable.
Using camera clipping also doesn't really work, for one it cuts everything in the scene and two GI doesn't penetrate the cut areas, they come out black.

[ficdogg]

I guess I figured one way to fake it.
Since my main texture will have a cubic projection, I couldn't just drop a texture in the opacity map and be done with it, but then I remembered the projection shader.
I plugged a circular gradient in the projector with a flat projection positioned where I wanted it, this way I can animate the gradient to sort of open and close the hole. It doesn't bridge surfaces but with a little blur on the edges, it doesn't look that bad.