Improve path coloring
Currently, all paths are rendered with the same colour.
Colouring each path depending on its order and type of order, i.e. reflection order 1 and diffraction order 2, could increase the information visible in the animation.
One idea would be to fade between colours. For example, starting at red with the direct sound (order 0) and fading towards yellow with increasing reflection order and towards blue with increasing diffraction order.