Rigid body dynamics let you create realistic motion using rigid body objects (referred to as rigid bodies), which are objects that do not deform in a collision. With rigid body dynamics, you can create animation that could be difficult or time-consuming to achieve with other animation techniques, such as keyframing. For instance, you can easily make effects such as curling rocks or billiard balls colliding and rebounding off each other, a set of die tumbling onto a crap table, or a clock's pendulum swinging back and forth.
