rope joint for this effect ?

[ThomasCartier]

Hi,

I would like to have multiple rigid bodies reacting to each others while keeping their distance with their neighbours.
Think soft body.

Angle top :

other angle to see the 3D:

I though of a rope joint, which is basically a generic joint (correct me if I am wrong) with limits set to the distance I would like.

The upper row will be fixed (no mass) and the others balls will fall down, with the effect of gravity. But I want each ball to keep its distance with its neighbors, freely moving and rotating, to keep the realism high. Like cloth, it can move in any direction but cannot retract or expand under normal condition.

1. I don't think I need a motor, since the gravity does it all. How to deal with that ?
2. to limit the calculations, I think I will only apply the joint on stride of 2 (avoiding a constraint A->B and B->A which is overconstrained)

Before I start, is there a better way to solve this in Rapier ?

Thanks,