to belong to only a single group, or very
	few groups.
</p>

<h4 id="collisionmask">
	Collision Mask
</h4>

<p>
	Collision masks are groups with which the rigidbody, trigger or other
	physics	construct can collide with. The object can be set to collide with
	several groups. Allowed collision groups are represented by bits in a
	bitmask.
</p>

<p>
	To determine if an object should collide with another object, each objects
	group bitmask and the other object's mask bitmask are logically ANDed
	together. If th