Bug / Crash Rod loses initial shape when forced

[josemendez]

There is rod with some bended initial shape and I push it into place where it's not possible to keep this shape fully. In my case it's some kind of tunnel collider.
The problem is that rod loses it's shape during that operation, like it had plastic deformation enabled. Meanwhile plastic creep and yield is set to 0.
Is that expected outcome?

Hi!

Plastic creep is the amount of deformation that is allowed to creep into the object's rest shape, once deformed past the plastic yield threshold. Setting it to zero disables plasticity, so no amount of deformation should be absorbed by the rest state of the rod.

Tested this by jamming a straight rod into a curved collider and then disabling the collider, but the rod immediately recovered its initial shape. Here's a video of the behavior you should expect using plastic creep = 1 (the rod retains the shape of the collider it was jammed into, even after the collider is gone) and plastic creep = 0 (the rod goes back to straight after the collider disappears).

However I think there might be something else wrong, because I tried to display restDarbouxVectors for each particle and (assuming I did it correctly) I doubt there should be NaN's there.
Is that bug and perhaps related to my problem?

Particles don't have darboux vectors (either rest or current), constraints do. They're accessed very differently. How are you looking at these values? Data lists in Obi usually are uninitialized, so unused areas of them may have any value.