A static 3D graph — relaxed once on the CPU then frozen — across which pulses of light travel node to node like current spreading: a per-node BFS graph distance from the current source drives an expanding ring in the shader, so edges light up in waves by hop-count and fade behind the front. Two offset fronts keep the flow continuous, the source auto-cycles, and pointerDown seeds a fresh BFS wave from a node picked by the cursor.