I’m trying to optimise my shadow volumes at the moment and obviously the biggest hit with the stencil/volume approach is it’s usage of fill rate. All I can think of so far is clipping the volumes against the geometry (Only for precalculated volumes), and segmenting my world into convex regions as then only the edges to the portals of these regions would be capable of casting shadows - which hopefully will help towards cutting down the number of edges I have to check (Useful for dynamic volumes) and go someway towards figuring out which volumes are visible in each region (Which I suppose could be precalculated also - which would involve clipping volumes to portals). I was wondering if anyone had experimented with similar ideas and if anyone knew of some good references to the actual process of carving up a triangle (soup) database into convex regions.
Also has anyone come close to combining a stencil shadow volume technique with some fiddling with destination alpha and projective texturing to produce soft shadows?