Tons of problems trying to simulate simple rope without elasticity

[Romahaaa]

Chances are the rope and the clip are colliding with each other. This will result in jittering, attachment offsets and all sorts of weird behavior as described in the "Pin constraints and collisions" section of the manual

Well, I am familiar with pin constraints. Everything was set properly - paper clip and pencil use category 1, rope uses category 0 with excluded cat 1 in collision mask for pins (the attached points).
I also had start2 and end2 pins which where far away from pencil and paper clip colliders with the same setup and start and end, but to make the experiment more simple I removed them. Nothing helped. After that I removed and added Obi Particle Attachments components again and this stop jittering... But the result is horrible still because none of your recommendations helped.

Crank up the amount of substeps (setting found in the ObiFixedUpdater). That will do. The manual contains a very detailed explanation of how and why the timestep and the amount of iterations affect the perceived elasticity of the simulation, and why using a smaller timestep is more effective

As I said before I tried to play with the different parameters: increase substeps/decrease time step/both of them. The timestep decrease works better comparing to substeps increase. To avoid the stretching effect I tried to increase distance substeps only but this works different way in 2 cases - when rope is not collided with surface or other colliders rope is not so stretchy but when it collides with a surface, it behaves like a metal string - the rope can push the attached object...looks really weird.
Here is an example using your RopeAndJoints scene: video

The simplest solution is to deactivate collisions between the end of the rope and the clip, as proposed in the manual.

Again, as I said before I checked ALL the documentation you have. I used as a sample your own scene and you can see the result in the video above. Please, stop refer to some solutions in documentation because IT DOES NOT WORK. Seems your asset is able to do some simulations without 2nd object attachment affected by physics. Rope just isn't a rope.

Same issue as above: there's a gap because the rope is colliding with the clip.

Nope, it's not. You can see clearly that your sphere and the rope in the same RopeAndJoints scene behave same way. video


Conclusion - I am pretty sure that you couldn't setup it the similar way I need it as well.