How to create flexible connections, such as a Keyring with a few keys?

Question

I would like to model an AR asset, like a keyring with a few keys in it. Obviously, I would like to show that it could be picked up and then because of physics, keys will naturally show up to the bottom of the ring. How could I do that in ARKit / Reality Composor / USDZ or anyway that iOS allows?

[EDIT] Andy Fedoroff perfectly answered my question about whether ARKit / Reality Composor could model a keyring with a few keys question. Are there other tools (such as Unity or UnrealEngine or Houdini) that could be used to model this kind of relationship? Will USD / USDZ support this kind of model?

Answer 1

Now there are no physics constraints (behaviours) in RealityKit 2.0 or in Reality Composer 1.5.

However, in SceneKit you can constrain two objects with SCNPhysicsBallSocketJoint.

class SCNPhysicsBallSocketJoint: SCNPhysicsBehavior

Test Chris Flannagan's project called iOS-Bimini-Ring-Toss to find out how it works.

Answer 2

There is a proposal "Rigid Body Physics in USD" that supposedly solve this issue.