Bioluminescence in black water, where each transient releases a shell that expands from a point at a finite speed. Organisms light only when the shell reaches them, so the flash sweeps across the frame instead of blinking, and several fronts cross at once.
Drawn with: a WebGL2 shader.
Reacts to and looks like: gpu, webgl2 and bioluminescence.
Family: Visualiser.
Runs in your browser. The preview above is the same program the renderer uses.