Rigid Body and Collision properties
This page lists the fields of the COLLISION and RIGIDBODY components. Field names and defaults were read from the oasisw.ai editor (version shown as OasisW 7e2aa65) on 2026-10-29. The steps for adding them are in Add collision, and the structure is in How physics works.
COLLISION
| Field | Default | Meaning |
|---|---|---|
| Type | Box | Shape of the area. Box, Sphere, Capsule, Cylinder, Cone, Mesh, Compound |
| Half Extents | 0.5, 0.5, 0.5 | Half the box's width, height and depth (meters). Doesn't follow the entity's Scale |
| Position Offset | 0, 0, 0 | Distance to move the area from the entity's center |
| Rotation Offset | 0, 0, 0 | Angle to rotate the area |
Fields by Type
On 2026-10-29 we switched through each Type and checked which fields appear. Position Offset and Rotation Offset exist for every Type.
| Type | Fields (default) |
|---|---|
Box | Half Extents (0.5, 0.5, 0.5) |
Sphere | Radius (0.5). Doesn't follow the entity's Scale (tested 2026-10-30) |
Capsule, Cylinder, Cone | Radius (0.5), Height (2), Axis (Y; X, Y, Z) |
Mesh | Convex Hull (off), Model Asset, Render Asset. Collides using the model's exact shape |
Compound | Offset fields only. Uses the combined shape of the child entities' Collisions. In a test on 2026-10-30, with Compound and a Rigid Body (Dynamic) on the parent and only a Collision (Box) on each of two children (no Rigid Body on the children), the two child boxes landed on the floor together and moved as one body (1 run) |
When we changed the Type and then switched back to Box, the previously entered Half Extents were still there.
Example: fitting a Plane
The Plane in a new scene has Scale 8, 1, 8. When you add Collision, the area is only 1×1 in the middle. In our tests, Half Extents 4, 0.5, 4 and Position Offset 0, -0.5, 0 covered the whole floor (step 4 of Add collision).
RIGIDBODY
| Field | Default | Meaning | Shown for Type |
|---|---|---|---|
| Type | Static | Static, Dynamic, Kinematic | All |
| Mass | 1 | Mass (kilograms) | Dynamic |
| Linear Damping | 0 | How much movement slows down (air resistance) | Dynamic |
| Angular Damping | 0 | How much rotation slows down | Dynamic |
| Linear Factor | 1, 1, 1 | How much it can move along each axis. At 0 it doesn't move along that axis | Dynamic |
| Angular Factor | 1, 1, 1 | How much it can rotate around each axis. To keep it from tipping over, use something like 0, 1, 0 | Dynamic |
| Gravity Scale | 1 | Gravity multiplier for this entity | Dynamic |
| Friction | 0.5 | How much it resists sliding | All |
| Restitution | 0.5 | How bouncy it is. At 0 it doesn't bounce | All |
| Rolling Friction | 0 | Friction when rolling | All |
When you choose Static or Kinematic, only Friction, Restitution and Rolling Friction appear (checked on 2026-10-29). These two types aren't affected by gravity or forces, so they have no mass or damping fields.
A box bouncing once after landing is caused by Restitution 0.5. In our tests, when a box was dropped from height 4, collisionstart fired again on each bounce, 2–3 times in total (Receive collision events).