If you want to create some pretty effects, add the concept of a velocity-texture which is added to agents velocity as they pass over it. Then let the user draw

If you want to create some pretty effects, add the concept of a velocity-texture which is added to agents velocity as they pass over it. Then let the user draw on the texture. Very cheap way to get interactivity. My own version from before compute shades were a thing (https://moritonal.github.io/force-particles/ https://moritonal.github.io/force-particles/)