Varphi - rigid body dynamics

Rigid body dynamics

On the right you can see an animation demonstrating torque free precession. An object that is rotating in free space with no external forces affecting it is aside from rotating also wobbling to conserve angular momentum.

I've started to build a small physics simulation library. Aside from building it I have documented the main physical, geometric and algebra issues. And also the numeric integration algorithms I use.

Rigid body dynamics using Euler's equations, Runge-Kutta and quaternions [PDF]