I would ( do ) use per-pixel lighting, so the whole question of polys is irrelevant to the way I do things. I also combine a static and dynamic lighting system in a pixel shader to get the best of both worlds.
But I have absolutely no idea what you're writing your engine in, so I'm not going to explain any further unless I know any of what I might say would be useful or relevant.
But I have absolutely no idea what you're writing your engine in, so I'm not going to explain any further unless I know any of what I might say would be useful or relevant.