[ODE] Holow geometry

[l.regini at diesgroup.com]

ODE geometries ( cylinders, boxes) are solid. I would like to implement
some kind of holow geometry. I am going to test for intersection with any
faces in the geometry collection. I have seen that for boxes collision
detection is sought by means of separating axis. Holow geometries are not
convex , is there an analogous efficient way of performing collisions?

Greets
Luca