Method of molecular dynamics
The MD method is suitable for a variety of classical problems (it can be used in mechanics, thermodynamics, etc.). The distinctive feature of MD is the fact that classical mechanics is used to describe the motion of particles. Interatomic forces can be represented in the form of classical potential forces (as the gradient of the potential energy of the system).
Building bubbles, squares, etc. (QT, similar to TChart Bubbles)
It so happened that there is no ready-made component for drawing bubbles in QwtPlot - like, for example, in TChart from Borland (Delphi). But it's no problem. All this can be done manually, and it's not very difficult.