But please, don't make the same mistake Conitec did with that Ellipsoid vs. Polygon collision detection! At least use capsule hull or give as possibility to chose between ellipsoid, capsule and box hulls. I can show you an old thread, where a lot of forum members where complaining about this (it was in Rants section), but jcl and mainly Conitec didn't give a damn thing. It would be really sad if you will develop such a great engine, but with the same mistakes...

The 3DGS collision system is AWFUL.

My best wishes!