Better method to change rod shape

[Qriva0]

Hi, I wonder if there is better way to keep rod shape (other than ObiBendTwistConstraintsBatch) without breaking physics too much.
I change shape of the rod to make it bend an it works, but final behaviour is not exactly "right".
The thing is that moving, pulling elastic rod makes everything very soft, forces do not propagate well, it's like pushing soft spaghetti. Keeping shape work in similar way, it the rod is stiff it bends very fast to target shape, but making it softer results in very slow "lerp like" change of rotation.

The thing is I want my rod to be overall soft enough, but at the same time change shape reasonably fast. On top of that I want to avoid situation where huge rigidity force the rod to break constraints, for example see image below. If rod changes shape with colliders around, it has no idea that the bend I set is not possible to do and the whole thing shakes, explodes, or is at least very unstable. 
I made system that moves bending slower and checks if lambdas in constraint are not too big, but it's clunky, I don't like my implementation. What else can be done?

   

[chenji]

it has no idea that the bend I set is not possible to do 

Why not? Are you using ObiCollider correctly for the cube? What's the mass ratio between the cube and the rod particle? And have you tried this? https://obi.virtualmethodstudio.com/manu...sions.html

[Qriva0]

Why not? Are you using ObiCollider correctly for the cube? What's the mass ratio between the cube and the rod particle? And have you tried this? https://obi.virtualmethodstudio.com/manu...sions.html

Imagine rod enclosed like picture above. Those boxes are static, can't be moved. Now you set all constraints to some angle, assume if boxes were not there, then rod would from almost circle, but there are boxes and rod is quite stiff to allow "reasonable time" to keep shape, and becausit's trying to ge this shape there is huge fight between constraints, movement of this rod is actually impossible by velocity, because it'spressed so hard orit even starts to shake, because solution is not available. Rod does not know it can't bend so much and it's not possible to form shape I set.

[josemendez]

The thing is that moving, pulling elastic rod makes everything very soft, forces do not propagate well, it's like pushing soft spaghetti. Keeping shape work in similar way, it the rod is stiff it bends very fast to target shape, but making it softer results in very slow "lerp like" change of rotation.

The thing is I want my rod to be overall soft enough, but at the same time change shape reasonably fast.

Material models can't really distinguish between internal and external forces - the former cause elastic materials to return to their "rest" shape, and the latter deform the object due to collisions, manipulation, etc: they react to all forces equally.

Because of this, it is simply not possible (or at least, not possible if you want to be physically accurate) to make an object that is easily deformed by external forces but returns to its plastic rest shape very fast - as it would essentially mean has different mass depending on the kind of force it's subjected to.

kind regards,