Tons of problems trying to simulate simple rope without elasticity

[josemendez]

This will not work in my case developing for AR.

Why not? you should be able to just scale the XR rig up. Never tried this to be honest, but some games I've played make the player larger or smaller in world space units. Unity's manual also mentions this:
https://docs.unity3d.com/Manual/configur...or-xr.html

Change the position and rotation of the XR Rig GameObject so it matches the position of the current Main Camera. If you’re applying a scale transformation to the Main Camera, make sure that you also apply this scale to the XR Rig GameObject. If you scale the XR Rig, it’s highly recommended to use a uniform scale across all three axes.

Thanks for the script!

Btw, did you notice the real size paper clip movement when rope doesn't move? The only way I found to fix it is to set rigidbody drag and angular drag to 1. Seems paperclip still receive some impulse from the rope even when it's static

Yes, this is probably due to floating point precision issues too. Objects suspended from a rope will always receive an impulse, if it's only to counteract gravity. However if their velocity is very small, Obi will apply an impulse of zero magnitude as it falls below epsilon. On the next frame, the body accelerates and the separating velocity between rope and object becomes once again enough for a corrective impulse to be applied. This will result in spurious movement or very small jittering.

Generally speaking, making things really small in games is just not a good idea. Precision issues will start plaguing both rendering and simulation, the only real fix for this is using doubles for everything but it's just too costly.