Scenes · Study 087
Fireworks on the River
Rockets climb over a dark river and burst into drifting sparks, with every explosion mirrored in the water. Click to launch your own.
What you're looking at
A rocket rises, slows under gravity and bursts at the top of its arc into ninety sparks thrown outward at random speeds. Each spark feels gravity and air drag, so shells open fast, hang, then droop. The canvas is only partly cleared each frame, which leaves the fading trails. The reflection is each spark drawn again below the waterline, squashed and dimmer.
The idea behind it
Firework colours come from metal salts: strontium for red, barium for green, copper for blue, sodium for yellow. Blue is the hardest to make well, because the copper compounds that emit it break down if the flame gets too hot.
Try this
Click or tap to launch a rocket from that point along the river.
