Yeah Sswift's renders a texture. I can't remember if it's cast directly on the polygons or if a proxy mesh is made and laid over the area ... but I think it's cast directly. At least in the old version which we used in AA. Aerial Antics had one problem though. Logic was updated at 60 FPS. I used to have this thing with game control being updated a lot and always went overboard ... but that would slow things down quite a bit. Anyway, Sswift's system is plenty fast ... you just have to use low polygon proxy recievers and such. Aerial Antics used all low polygon collision detection and shadow recievers.
Personally, I think it's a bit late in the game to develop a new shadow system. B3D is already old and on the way out sometime next year once BMax has it's 3D module. If you plan on releasing a game between now and then ... just use Sswift's system and save yourself a few weeks work. If you're not actually making a game and just doing it for the intellectual stimulation ... have fun and good luck.
Personally, I think it's a bit late in the game to develop a new shadow system. B3D is already old and on the way out sometime next year once BMax has it's 3D module. If you plan on releasing a game between now and then ... just use Sswift's system and save yourself a few weeks work. If you're not actually making a game and just doing it for the intellectual stimulation ... have fun and good luck.