Help Need fixed width rope with no stretching at all

[josemendez]

Hi guys, I play with Obi Rope 6 for few days and I can`t resolve one simple scenario. I want rope with fixed width(for example 5 meters) and want no stretching at all. But when I add Obi Particle Renderer I see how particles is group 2 by 2 and between every group of 2 particles there is a gap(in pink color) which is stretching. I play around with Obi Solver substeps(set it to 8), with Obi Solver Distance constraint(set it to 30). But I can get simple non stretchy rope.

That sounds like you're simply forcing the rope to overstretch. With 8 substeps, there should be zero stretching. Are you using static attachments at the ends of the rope, by any chance?

(in pink color)

Did you assign a material to the rope at all? Unity will use a flat pink color to draw objects with no material. This is standard Unity behavior, not related to Obi.

Second scenario I testing: Just add a bar(cube with sizes 0.2x0.2x4) add Obi collider to it and try to move the rope through this bar. For some time the rope is collide with the bar but in some moment, when the gap between the particles is big enough, the bar just passes through the rope.

This is completely normal. If you overstretch the rope by pushing a collider trough the rope or viceversa (I assume you just move the collider by setting its position), at some point the rope will miss collisions. In real life, either the bar or the rope would have snapped.

Simply use forces to move the bar (you will need it to be a rigidbody) instead of forcing it by setting its position, or use dynamic attachments to move the rope. This way, the rope can stop the bar from moving once it's fully stretched.

You can use masses (both for the collider and the rope) to control how easily they push each other. Note this applies to any existing physics engine.

These are basic physics concepts (force coupling, masses, etc), it’s assumed you’re already familiar with them when using Obi.

Let me know if you need further help.