Physics worlds

Real physics, in a world file.

Bodies, robots, joints and policies are declared in a world.tsx. The engine steps it 240 times a second, and records every frame and every command.

An SO-101 arm in simulation lifts a white cube from a blue pad toward an orange pad; a translucent blue copy of the arm shows where its policy plans to be half a second later.
Recorded in the workbench: the so101-cube world, its arm driven by a pick-and-place policy. Simulated.

Case study · one arm, one cube

Six deliveries in a minute, 31 times faster than real time.

The world ships with the workbench: an SO-101 arm, a bench, two pads and a 25 mm cube. Its pick-and-place policy moves the cube from pad to pad and back. The study stepped it for 60 simulated seconds and found where the cube came to rest.

physics steps, 240 a second
14,400
deliveries, the first at 7.6 s, then one every 9.4 to 9.7 s
6
policy commands, 20 a second
999
of this computer's time for the 60 s, 31× real time
1.9 s

Simulated

The cube's x position over 60 simulated seconds
الأرقام
The cube's x position over 60 simulated seconds
Simulated time (s)No dragsFour drags
0-90 mm-90 mm
2-90 mm-90 mm
4-90 mm-90 mm
677 mm77 mm
8100 mm100 mm
10100 mm100 mm
12100 mm28 mm
14101 mm-142 mm
16-91 mm-155 mm
18-90 mm-156 mm
20-90 mm-89 mm
22-90 mm-90 mm
24-90 mm-17 mm
26101 mm131 mm
28100 mm131 mm
30100 mm131 mm
32100 mm131 mm
3444 mm131 mm
36-90 mm97 mm
38-90 mm29 mm
40-90 mm30 mm
42-90 mm88 mm
4461 mm100 mm
46100 mm100 mm
48100 mm22 mm
50100 mm-140 mm
52102 mm-140 mm
54-89 mm-140 mm
56-90 mm-140 mm
58-90 mm-140 mm
ProvenanceFile cloud://global/worlds/so101-cube/world.tsxOutput case-studies/physics-worlds/stats.jsonTool scripts/sites/case-studies.mjs physics-worlds (sim-engine.js, Rapier)Ran on This computer (dell-gb10-1, 20 cores)When

The same minute, with drags

Drag the cube away: the policy went back twice in four.

A drag is a command like any other: grab the cube, pull it for 0.4 s, let go. The study dragged it four times to points on the bench. After the drags at 12 and 36 s, the policy took the cube to a pad again. After the drags at 24 and 48 s, it did not go back in the 12 s that followed. That is the kind of finding a world is for, before a real arm is involved.

Open the worldSee replay

Simulated

drags, each recorded as a grab and a release
4
recovered: deliveries at 20.7 and 43.7 s
2 of 4
deliveries in the minute, against 6 without drags
3
commands refused by the engine
0
ProvenanceFile cloud://global/worlds/so101-cube/world.tsxOutput case-studies/physics-worlds/stats.jsonTool scripts/sites/case-studies.mjs physics-worldsRan on This computer (dell-gb10-1)When

Put your robot in a world.

Describe a scene in a world.tsx, or ask an agent to write one. Step it, drag it, and every step is on the record.