Colliders

A collider gives a body its shape. Add one (or several) alongside a Rigid Body. Several colliders on one entity combine into a compound shape.

Shapes

Collider	Shape	Key fields
Box	A box	Half Extent (half-size per axis)
Sphere	A ball	Radius
Capsule	A pill, along local Y	Radius, Half Height
Cylinder	A flat-ended cylinder	Radius, Half Height, Cap Radius
Mesh	A mesh’s geometry	Mesh, Convex
Terrain	A terrain heightmap	(needs a Terrain on the same entity)

Every collider also has:

• Translation Offset and Rotation Offset, to place the shape relative to the entity, for example a 90° rotation lays a capsule on its side.
• Physics Material, the surface’s friction and bounce, see Materials & Destruction.
• Is Trigger, makes it a non-solid trigger volume, see Collisions & Triggers.
• Affects Navigation, whether the shape is baked into navmeshes.

Mesh colliders: convex or concave

A Mesh collider builds its shape one of two ways:

• Convex (Convex on), a convex hull of the mesh. Valid on dynamic bodies. Use it for props.
• Concave (Convex off), the exact triangle mesh. Valid only on static or kinematic bodies. Use it for level geometry.

Prefer a primitive shape (box, sphere, capsule) over a mesh collider wherever you can, they are far cheaper to simulate.