Collision shapes

For setup, see physics.

Choose a shape

Shape Mode > Auto chooses collision from the geometry and physics mode:

Geometry	Static and Animatable	Rigid and Trigger
Closed, outward-facing convex solid	One convex hull	One convex hull
Other geometry	Concave triangles	Convex decomposition

A convex hull encloses source points and fills recesses. Decomposition divides geometry into pieces to preserve openings. Convex - Single and Convex - Multiple select these explicitly. Concave supports Static and Animatable only.

For an inward-facing room, Auto preserves face winding, the direction each face points. Characters inside collide with the floor. Outside characters can pass through the ceiling’s back face. Convex - Single fills the room and blocks its interior.

Geometry limits and warnings

Decomposition preserves significant openings and disconnected components within Approximation Tolerance. Max Hulls limits pieces. If decomposition cannot meet both limits, Meshy warns and produces no collider.

A triangle plane supports Static collision. Rigid and Trigger require volume. Flattened solids lose collision and warn. They remain editable. Valid geometry restores collision.

get_collision_representation() returns the Auto representation or unavailable/stale status.