Rigid bodies
Rigid bodies allow physics simulation to be applied to your Entities
Giving physics to Entities
In editor:
Add aRigidBodyComponent in the editor by seleting the entity in the scene hierarchy, clicking 'Add' > 'Rigid Body Component' under the 'Components' header.
In code (C++):
PhysicsMaterial material;
material.mass = 10.0f;
crate->AddComponent<RigidBodyComponent>(RigidBodyComponent {
.physicsMaterial = material
});
Mass defaults to 0, which makes the body static: other bodies collide with it, but it doesn't move. Set a mass above 0 to make it dynamic.
Physics material
| Property | What it does |
|---|---|
| mass | Mass of the body, 0 == static, immovable |
| friction | Surface friction. Starts at 0.5. |
| restitution | Bounciness. Starts at 0. |
To give a body a starting velocity, set initialVelocity or initialAngularVelocity on the component
Shapes
The shape defines the collision volume. Make one with Assets › Add... › Physics Shape, and assign it to the component's collision shape. You can pick from:
- Box, Sphere, Capsule and Plane.
- Convex hull, wrapped around a mesh.
- Compound, a mesh decomposed into convex pieces. Use this for complex geometry.
- Height field, for terrain.
Plane and height field bodies are always static, whatever their mass.
If no shape is set, a box fitted to the entity's bounds is used.
In multiplayer
The server is the authority, and simulates physics for the world.
On clients, replicated bodies don't simulate: they follow the positions and velocities the server sends, interpolating between updates. Bodies that aren't replicated are simulated locally on each client. More in replication.