ChipmunkConstraints are things like joints or motors that constrain the motion of two bodies relative to each other.
| bodyB | The other body that the constraint attaches to. |
| impulse | The magnitude of the impulse this constraint applied last frame. |
| maxForce | Maximum force the constraint is allowed to use. |
| errorBias | Rate that error (stretching of the constraint) is fixed. |
| maxBias | Maximum rate that constraint error is fixed. |