Help Weird Collisions

[josemendez]

And then set the distance stretching to 0. But now the rope shrinks and then stretches when moved. It has stopped colliding with everything.

That's worse than before! You're asking the rope to shrink to 0% of its rest length: essentially, to try and collapse into a point as much as possible. You should set it to 1 (100%) in most cases.

From the manual: http://obi.virtualmethodstudio.com/tutor...aints.html

Stretching scale

This is a scale factor for the rest lenght of each constraint. The initial rest lenght of any distance constraint is a fixed value set by the ObiActor using it. You can increase this distance (making the constraints expand) by setting a scale factor > 1, or reduce it (making the constraints shrink) by using a scale factor < 1.

Most other settings in your screenshots make no sense either:

- In the solver, distance constraints relaxation is set to 0.1. That means that distance constraints will only have 10% of their full effect. However you're using 50 iterations on them, so this is basically just burning performance: you spend a lot of time enforcing constraints that are as good as deactivated, and the resulting rope will be extremely stretchy and noodle-like. Set the relaxation to 1 (100%) so that distance constraints can be fully enforced, and then you'll only need a few (3-4) iterations. From the manual: http://obi.virtualmethodstudio.com/tutor...olver.html

Relaxation Factor
Values lower than 1 will only partially enforce constraints. For instance, with a relaxation factor of 0.25 constraints will only have a 25% of their normal effect.

- Your bend compliance is set to 0.54 m/N. That's a lot. The result is that the rope will be allowed to bend so much that you won't notice any difference between using bend constraints or not, so this is also just burning performance for no good reason. Either set compliance to a smaller value (eg 0.0001) or deactivate the constraints entirely if you're not using them.

- Your rope is at maximum resolution, yet you're using surface collisions. Again, this will just make the simulation extremely costly for no reason. Either reduce your resolution (0.25-0.5 is a good range) or disable surface collisions entirely. See the "tips" section in: http://obi.virtualmethodstudio.com/tutor...sions.html

Let me know how it goes,

cheers!