Particle Playground

Pick a material above
and drag to draw

Draw a bowl with Wall and pour in Lava. Add Water to cool it into falling stone and rising steam, then watch the steam condense into water. Try wood or oil beside the lava to see it catch fire. Pause first to assemble your experiment.

Sand: Falls and piles up. It sinks through water and oil.
Water: Flows and levels through connected pools. It extinguishes fire and burning wood, and cools touching lava into stone while becoming steam.
Oil: Flows more slowly than water, floats on it, and catches fire.
Fire: Ignites oil and wood, rises, and eventually goes out.
Wall: A permanent barrier until you erase it. Turn on Snap walls, or hold Shift while drawing, for straight lines.
Wood: Falls and piles up as loose particles, floating on water and oil. Fire burns it into ash with a little smoke. Water puts it out; lighting it again uses the remaining fuel.
Smoke: Rises through open space, collects beneath barriers, and quickly fades away. Liquids push it aside.
Ash: A powder left by burned wood. It falls, settles, and sinks through liquids.
Lava: A slow, dense liquid that ignites touching wood and oil. Water cools it into stone and becomes steam. Walls contain it; it does not melt sand, ash, or stone.
Stone: Forms when lava cools. These heavy particles fall and pile up instead of hanging in the air like walls.
Steam: Forms from water touching lava. It rises through open space, then condenses back into water.

Build and experiment

Choose a brush size, then drag on the canvas. Hold still to keep pouring while the simulation runs. Particle brushes fill open space without replacing solids or liquids. Fire lights fuel instead of erasing other materials. Use Eraser to remove material, including walls, or Wall to build barriers. Drawing while paused lets you prepare a scene.

Pause / Resume stops or starts the simulation. Step advances one tick while paused. Undo restores the whole scene to before your last stroke or Clear that changed it and pauses it, so you can change the setup before running it again.

Keyboard: Space pauses or resumes, period (.) steps while paused, and Ctrl+Z or Command+Z undoes. Shortcuts leave text fields, menus, and Help controls alone.

Experiment with different elements to create unique interactions and patterns!