unity-physicscore2d-chains-api

Call PhysicsChain.Create with a PhysicsBody, either a ChainGeometry or a ReadOnlySpan of Vector2 vertices, and a PhysicsChainDefinition. The chain must have at least 4 points, and consecutive points must be separated by more than the linear slop distance.

PhysicsChain is the runtime shape attached to a body that produces connected chain segments. PhysicsChainDefinition is the configuration struct specifying isLoop, contactFilter, surfaceMaterial, and triggerEvents used when creating the chain.

Yes, set isLoop to true in PhysicsChainDefinition to form a closed chain connecting the first and last vertices. Loop chains calculate ghost vertices automatically, while open chains have no collision on their first and final edges.

Chain shapes are specifically designed to avoid ghost collisions by providing a smooth continuous surface, unlike separate edge shapes. If artifacts appear, verify the chain does not self-intersect and that point spacing exceeds the minimum distance requirement.

Yes, use UpdateVertices with a ReadOnlySpan of Vector2 and an isLoop flag. The vertex count and loop setting must match the original creation parameters, otherwise a warning is issued, and changes may cause overlaps or tunneling.