Camera Perspective?

I've got a nice lightning script that creates elaborate lightning effects at the "gates" of the temple in my new map. The lightning moves and arcs, serving as a stunning barrier to anyone approaching.

However, as we all know lightning is rendered last, so the lightning is visible over top of anything that might approach.

I could, of course, use units in the model of the Ziggurat missle, which may be what I end up doing anyway. But, does anyone know of a good algorithm for determining the camera location, and thus what is in the line of sight? If I know such an algorithm, I might be able to make the lightning selectively visible.