Hierarchical N-body solver

Fast Multipole Gravity Lab

An adaptive quadtree Fast Multipole Method for softened 2D Newtonian gravity. Multipole moments flow up the tree, far-field interactions are translated in one shot, and only nearby leaves are summed exactly.

M2M → M2L → L2L → P2P

Telemetry

Particles– FPS– FMM solve– Tree nodes– M2L pairs– Sample err–

SettingsFMM · N-body

Scene

Preset

Particles1024

FMM solver

Expansion order3

Separation ratio1.60

Leaf capacity32

Physics

Gravity G0.65

Softening ε0.018

Timestep0.003

View

Trails Quadtree Accel vectors Sample error

Click to inject a particle cloud · Shift-click to add a massive body · Space pauses