Mathematical Marbling added

A basic version of mathematical marbling has been added.

It simulates dropping droplets of ink on water.
Each time you click a new drop of a random color is added and the previous droplets deform accordingly.

Based on the video tutorial by The Coding Train, 183 mathematical marbling
Knowing where the mouse click happens is based on this snippet by rdb
The droplets are GeomNodes, thin triangles arranged clockwise, and the vertex coordinates of the previous droplets are updated with each new drop. I used the information from this chapter of the panda3d manual.

I learned a lot, especially how to create geometry from scratch and edit it each frame.
It's actual use in a game is debatable, but I enjoyed making it.
The marbling is fun too.