Hierarchical N-body solver
Fast Multipole Gravity Lab
An interactive O(N) adaptive quadtree simulation of softened 2D gravity using Cartesian Taylor expansions.
M2M → M2L → L2L → P2P
Particles
1024
FPS
0.0
FMM Time
0.0
ms
Tree Nodes
0
M2L Interacts
0
Force Error
0.000%
Scene
Spiral galaxy
Binary galaxies
Orbital ring
Cold collapse
Three-body tracers
Particles
1024
Reset
Pause
Step
FMM Solver
Expansion order
3
Separation ratio
1.60
Leaf capacity
32
Physics
Gravity
0.65
Softening
0.018
Timestep
0.003
View
Particle trails
Quadtree overlay
Acceleration vectors
Auto sample error
Click to inject a particle cloud · Shift-click to add a massive body · Space pauses