A velocity limit below which objects will not bounce. 2 is a good base value.
Gravity vector, in m/s^2.
Rate to run the simulation, in frames per second. Should be less
than the update/render rate.
Type of collision solver to use. If the type is kFastNormal or kFastFast,
setEnableCCD() can be called on a rigid body to enable CCD collisions for it.