Seeds and repeatable loops

Every Bounceloop simulation is determined by three things: the mode, its settings, and the seed. Give the engine the same three and it plays the same run, every time, on any computer.

What the seed does

The seed starts the random number generator that picks things like the ball's launch direction or where spikes sit. Change the seed and you get a different but equally valid run. Keep it and nothing moves.

Randomize and lock

• Randomize picks a new seed so you can look for a run you like.
• Lock keeps the current seed, so changing a setting alters the look without reshuffling the run.

Why the engine is fixed-step

The engine advances in steps of exactly 1/120 of a second. It does not speed up or slow down with your computer, which is what makes runs repeatable and lets the exporter render any frame exactly.

Sharing

Presets can be shared as a link that carries the mode and settings. Include the seed when you want someone to see the same run you saw. If you change a setting afterwards, the run can change too, so lock your seed before fine-tuning.