The simulation consist of the following classes:

Force -- container class for an interacting force
Node -- implements the node, e.g. ball, vertex, ...
Main -- the main class for the whole program, initializes coin3d
Particle -- implements the particle
Simulation -- the main class for the simulation, creation of objects,
		builds Inventor node graph, collision detection and handling
Spring -- implements the spring

For numerical integration leapfrog is used, RK4 behaved strange, dunno why.