Direct3D as Line-Of-Sight calculator?

Is it possible/feasible to use Direct3D to determine line of sight? It should be, in theory, as it would have to determine that sort of thing for determining how much of a poly to render when it is partially obscured, or at the very least for lighting and shadows.

This isn't crucial to me, but I am quite curious ATM.

If you're trying to use use line of sight for lighting and shadows then you're basically getting into ray-casting. It is possible, in fact it's quite easy, but the computation over-head is extreme. I wouldn't recomend using this method for lighting and shadows. I would instead use mip maps.

denmietser

It should be, in theory, as it would have to determine that sort of thing for determining how much of a poly to render when it is partially obscured

Not really, all it does is calculate a depth value for each pixel, and the one with the lowest depth is stored in the depth-buffer. Thats why, if you turn depth buffering off, polys appear in the order they are rendered.

I should clarify my post. DirectX comes with the D3DX library which is very seful for dermining line of sight calculations. Direct3D does not use this method for rendering because of it's computational over-head. But it is possible. Just not how you might be thinking.

denmiester