Scene
Ball race
A race down a vertical track taller than the screen, with pegs and bars drawn from the seed. The camera follows the leading ball and never looks back.
Open Ball race in the editor
Parameters
The same controls as the editor, with the same range. The default is what the example page uses.
| Parameter | Range | Default |
|---|---|---|
| Track length | 20 – 200u | 70 |
| Racers | 2 – 12 | 5 |
| Obstacle density | 0.4 – 2 | 1 |
| Gravity | 1 – 40 | 14 |
| Bounciness | 0 – 1 | 0.5 |
How it usually ends
Measured by the engine with the default configuration over a fixed sample of seeds. No number here is an estimate.
- Seeds in the sample
- 40
- Escapes
- 100%
- Settles
- 0%
- Times out
- 0%
- Collisions (median)
- 195.5
- Duration (median)
- 24 s
- Climax (median position)
- 21%
- The fraction of the video where event density peaks. Close to 100% means the best moment is at the end.
Seeds that end well
No seed in the sample reached the search threshold. These are still the best ones.
- seed2421112score 69 out of 100197 collisions20.9 sescapeOpen seed 2421112 in the editor
- seed2211654score 63 out of 100211 collisions24 sescapeOpen seed 2211654 in the editor
- seed1059635score 60 out of 100205 collisions21.3 sescapeOpen seed 1059635 in the editor
- seed431261score 60 out of 100185 collisions22 sescapeOpen seed 431261 in the editor
- seed3049486score 59 out of 100178 collisions22.6 sescapeOpen seed 3049486 in the editor
Frequently asked questions
How do I make a Ball race video?
Open the scene in the editor, adjust the parameters, try a few seeds and export to MP4. Rendering happens in your browser and costs nothing.
Why does the same seed always give the same video?
The simulation is deterministic: fixed-step physics and seeded random numbers. The same seed with the same parameters reproduces the same video on any machine.
How long is a Ball race video?
The video ends when the scene ends. The median duration measured in the sample is in the outcomes section, and the seed search shows each candidate's duration before rendering.
Can I use the video on TikTok, YouTube and Instagram?
Yes. The export is a vertical video with audio, ready for Shorts, Reels and TikTok. On the free plan it carries a discreet watermark.
How do I pick a seed that ends well?
Use the editor's seed search: it simulates dozens of variations without drawing and ranks the ones with a late climax. The seeds on this page came from the same heuristic.
Make your own variation
Open the scene in the editor with one of the seeds above, or let the search find another.
Open Ball race in the editor