All simulations

An open-world of 30+ canvas simulations driven by your cursor. Boids, black holes, fireflies, slime mold, Lorenz attractors, and more. 32 simulations, all driven by your cursor, all running on plain HTML5 canvas with zero dependencies.

Browse all 32

• AutumnA central maple drops leaves across an autumn scene. Cursor pushes leaves around; click sends a gust through the canopy.
• Ball pitA box of bouncing balls with circle-circle collisions. Cursor repels, click shoves them outward, periodic earthquakes jolt the pit.
• Black holeKeplerian particles spiral into an accretion disk; foreground gets stretched and swallowed, background galaxies stay put. Click fires polar jets.
• BoidsReynolds 1987 boids — separation, alignment, cohesion — running on a spatial hash grid. Cursor attracts the flock; click repels. Torus wraparound.
• BubblesBubbles rise toward the surface as god-rays slant down; cursor draws them into a swirl.
• Chladni plateSand on a vibrating plate. Cursor x and y set the (n,m) mode; particles step along the gradient until they cluster on the nodal lines.
• ClothPinned verlet cloth grid in ambient wind. Cursor pushes the mesh; mouse-down grabs the nearest free node and drags it.
• DogA dog with a state machine — runs to chase the cursor, sits when close, sleeps when idle. Click for a heart or a 'WOOF'.
• FirefliesFireflies wander a dark grass field; cursor is a lantern that pulls them in. Click flares the lantern and scatters the swarm.
• FireworksRockets launch from a skyline silhouette and burst into chrysanthemum, willow, ring, or crossette patterns. Click for a burst.
• Fish pondA school of goldfish in a dark pond; they flee from the cursor while light caustics ripple the surface.
• GrassA meadow of tall grass blades sways in wind, butterflies flutter low above the tips. Cursor pushes blades and butterflies.
• Gravitational lensingInverse ray-tracing through a Schwarzschild deflection — the cursor is the lens, distorting a starfield. Click stacks a mass pulse.
• Hot air balloonA hot air balloon drifts toward the cursor across a sunset sky; click fires the burner for flame and lift.
• Lightning treeLightning branches downward from clouds toward the cursor in a fractal pattern. Mountains silhouette the horizon.
• Lorenz attractorFour points integrate the Lorenz system (σ=10, ρ=28, β=8/3) — the butterfly attractor. Cursor pulls the integration target; click reseeds.
• Bar magnetA bar magnet rides the cursor and rotates with cursor velocity. Iron filings align to the dipole field and drift toward the nearest pole.
• Horseshoe magnetHorseshoe magnet with two parallel poles. Filings trace the arched field between the tips and drift toward the nearest pole.
• Meteor showerMeteors streak diagonally toward a horizon silhouette. Cursor casts an atmosphere bubble that ignites them; click launches a large meteor.
• MurmurationA starling-style flock moves as one mass against a sunset sky and tree silhouettes. Cursor attracts and disturbs the flock.
• NeuronsTwo nearby neuron fields linked by only a handful of short bridge connections. Click starts a session — nearest neuron fires, then pulses spill unpredictably between the two clusters.
• Newton's cradleSix steel balls on strings with 1D momentum exchange. Cursor near a ball nudges it; mouse-down + drag pulls it back to swing.
• Pendulum chainVerlet rope with 20–50 nodes hung from a top anchor. Cursor near the tip grabs it; click flings it. Ornaments dangle from intermediate nodes.
• SheepdogCursor is the dog. Sheep flee it; once inside the pen they settle.
• Slime moldPhysarum agents sense, turn, step, deposit; the trail map diffuses and decays each frame. Cursor deposits attractors; click drops a burst.
• SnakeA segmented snake follows the cursor, wanders if idle. Click for a brief speed boost; mouth opens and tongue flicks near the cursor.
• SnowflakeThree tiers of snowflakes in sinusoidal drift. Cursor pushes them outward; flakes accumulate as a heightmap, click clears a depression.
• Solar systemEight planets at compressed orbits seeded from J2026.0; Earth's moon, Saturn's ring. Cursor x scales angular velocity; y tilts the plane.
• SubmarineA submarine glides toward the cursor through kelp and drifting plankton; propeller spins behind it.
• Sun attractionPlants probe 18 angles for sun-aligned open sky and lean to grow there; conifers cast shadow polygons. Cursor is the sun.
• Water boxParticle-based water with surface tension and gravity in a box. Cursor pushes the body of water; click creates a splash impulse.
• Water rippleHeight-field water surface — top-down, depth-tinted. Cursor and clicks push concentric waves; foam highlights tall crests.

By category

• PhysicsInteractive physics in the browser — verlet cloth, particle water, magnets, momentum exchange, vibrating plates.
• Chaos & emergenceStrange attractors, slime mold pathfinding, branching lightning, neural propagation — emergent behavior from simple rules.
• Life & natureBoids, murmurations, fish schools, fireflies, sheepdogs, autumn leaves, growing plants — cursor-driven nature scenes.
• Space & astronomySolar system, black hole accretion, gravitational lensing, meteor shower — interactive astronomy in the browser.