Feedback Pinholes: new component for ropes

[josemendez]

However, the moment I disable the range the stability collapses and they can no longer keep their positions and it starts to jitter. This happens even with friction set to 1 and motor force to infinity. I would expect them to keep their positions as though they were clamped with infinity friction. The constrains slide over each other so to speak. I could get the cable car example to do the break down similarly if I gave it a high enough speed.

Constraints are completely independent of each other. This is a core design principle of most physics engines, necessary for efficiency reasons: multithreading can only work on constraints that don't share particles as otherwise they'd run into race conditions - multiple threads trying to modify the same particles at the same time, leading to undefined behavior.

For pinholes this means they have no notion of their relative position/distance to each other: they can (and sometimes will, as you discovered) cross over each other.

In practice, making a constraint be "aware" of another constraint means they must act on each other's particles so they effectively become a single, larger constraint. So I guess what you'd want in your case is an uber-pinhole of sorts that constraints multiple particles to multiple points in multiple bodies, and also constrain their relative positions along the rope.

If i were to set friction to 0, I can understand that happening as there is nothing in the constraint that forces them to be ordered and distanced to eachother with respect to their mu. However, It would be very useful if there were a setting to force them to have a certain mu offset toward each other.

Note this may happen even if friction is 1 and motor force is set to infinity, as these parameters affect velocity but don't directly affect position, which other constraints might modify: the only sure-fire way to prevent this is by setting constraint limits.

Another issue I see is that if I disable "Limit Range" and enable it again, the attached offsets of the constraints seem to be zeroed.

Will take a look at this, as it indeed sounds like a bug. Thanks for reporting it!