title: CANNON.js custom rigid body
body: <p>I'm tinkering a bit with cannon.js and three.js, and i wish to have terrain. This would require a custom <code>CANNON.RigidBody</code>. I've seen the predefined shapes, like plane, box and sphere, but i cannot seem to figure out where or how cannon defines its shapes. is there a way to create a <code>CANNON.RigidBody</code> from a <code>THREE.Geometry</code>, or <code>THREE.Mesh</code> or even define it poly, by poly?</p>