Slowly weaving into a sphere, all threads have different, sort of random orbits. While running different paths, some more or less stick around the same orbits, others wander more wildly; some run faster, some slower; some threads are thicker, some are thinner. The random characteristics can be set differently so that each thread has its own "character" different from others, yet they cross each others and slowly evolve and end up a sphere made up of these running threads. Every sphere ends up differently each time the program is run. The video is taken at 24 frames/s. The actually program can run at much higher frame rate and actually looks smoother and the colours are better.
To see the graphics more clearly, here is the video directly dump from computer screen output (after converting the size from 1080p to 720p) while the program is running. In the videos, I used the mouse cursor to move the spheres around, and pressed a key to restart everything again randomly when the woven spheres get too dense and thick (since the lines are very fine, recommend to switch to 720p in your player to see the graphics more clearly).
In the above videos, to choose a few colours that mix good visually, I adapted a few basic colours from two paintings by Rogier van der Weyden. Not in any sense trying to diminish or mis-interpret the original work, but how much can be done with just basically repeated use of a few common colours in religious paintings at those times is quite amazing. These colours sure has their specific religious meanings at those time. But also I think merely the recurring use of these colours in countless number of paintings in the Middle Ages has already given them some special meanings of their own.
Below are other runs with different colour schemes. For the first one below I intentionally used only grey tones. All videos have no sound or music background, which I think is better this way.
1920x1080 screenshot from a run with some different settings.