Gravity does the drawing
There is no brush engine and no prerecorded path. One softened inverse-square sun sits at the centre of the stage, and everything you see — rosettes, braids, comet smears — is a body honestly falling around it while a pen of light records where it went.
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01
Launch
Tap anywhere and a planet drops into a near-circular orbit — tangential velocity
√(GM/r), jittered a touch so rings precess into rosettes instead of stacking. Drag and release to slingshot, guided by a dotted preview that runs the exact same integrator the planet will use. -
02
Fall
Every frame, each planet feels
a = GM/r²toward the sun, integrated with semi-implicit Euler at four substeps. The integrator is symplectic — energy barely drifts — so a tapped-in ellipse keeps its shape for minutes, slowly rotating into a flower. -
03
Paint
Each substep strokes the planet's path onto a canvas that never clears: a wide whisper of halo, then a bright core, both composited additively so crossings bloom toward white like long-exposure film. Fast near the sun means a thin filament; slow at apoapsis, the ink pools wide.
semi-implicit Euler · 4 substeps / frame · additive 'lighter' compositing · 0 libraries in the simulation
Six scores, ready to play
A composition is nothing but a seed list — radii, angles, directions, eccentricities. Every thumbnail below is being simulated in your browser right now, not loaded from an image. Click one to hand its score to the instrument above.
no images were harmed — each card is ~1,500 physics steps rendered at page load
Leave with something printable
One click composites your session onto a 1600×2000 plate: the palette's deep background, your trails fitted inside a hairline frame, the sun and surviving planets stamped in, and a caption block set like a gallery label.
- 1600 × 2000 px PNG — crisp at A3
- Palette name signed in italic Fraunces
- Launch count, date and swatch strip stamped
- Nothing uploaded — rendered and saved locally