Rigid bodies
Solid objects that tumble, bounce, and stack — boxes on a floor, dice in a cup, a cascade of crates.
A rigid body keeps its shape no matter what hits it. Drop a stack of blocks, knock them over, let them settle — the Rigid Body Sim node runs the whole thing on the GPU so it stays real-time even with a crowd of objects.
Getting things falling
Feed some geometry into simulation.rigid_body and wire it into a simulation.particle-style scene — or, more simply, drop your shapes into a Physics World and give it a ground. Each separate piece of geometry becomes its own solid body. Add a floor (a Physics Collider, or the built-in ground), press play, and gravity does the rest.
Any plain geometry you send into the physics world becomes a rigid body automatically — you don't have to flag it. Scatter some boxes, wire them in, and they'll fall and stack with no extra setup.
The pose of each body — where it ends up and how it's rotated — is written back onto your shapes as they tumble, so the original look is preserved on the way out.
The three controls that matter
Most of the feel of a rigid sim comes from three properties:
Mass — how heavy a body is. Heavier bodies shove lighter ones aside and are harder to push around.
Friction — how much surfaces grip. High friction makes objects slow and stack cleanly; low friction lets them slide like they're on ice.
Restitution (bounciness) — how much energy survives an impact. Zero means a dead thud; high means a lively bounce.
Tune these until the stack settles the way you want. A pile of bricks wants high friction and low bounce; a handful of rubber balls wants the opposite.
The physics world
Bodies don't simulate in isolation — they live in a shared world that also holds the floor, walls, gravity, and any forces. Everything wired into the same Physics World collides with everything else and obeys the same gravity.
Colliders — static surfaces to land on and bump into (floor, ramps, walls).
Gravity — the world's downward pull; turn it down for a floaty, slow-motion feel.
Forces — wind, vortexes, and attractors from a simulation.force_field push bodies around as they move.
You can also pin bodies together with joints — see Joints & constraints — to build hinges, chains, and ragdolls.
There's no separate "CPU physics" mode to choose. The solver runs on the GPU, which is what keeps large stacks and piles real-time.
Collisions and contacts
Bodies collide with each other, with static colliders, and with Distance Field shapes used as collision boundaries. Anti-tunnelling is always on, so fast-moving objects won't shoot straight through a thin floor — there's no separate switch to enable.
If you want to react when things touch — trigger a sound, spawn particles, change a colour — use a query.trigger to catch the moment two bodies meet.
Parameters
| Parameter | Type | Default |
|---|---|---|
input | Any | — |
body_type | String | "Dynamic" |
collider_shape | String | "Mesh" |
mass | Number | 5 |
friction | Number | 0.500 |
restitution | Number | 0.300 |
iterations | Number | 10 |
damping | Number | 0.010 |
strength | Number | 1 |