Help contact.stickImpulse always 0, Closed loop ObiRope Collision fails

[alicecatalano]

Hi,

I'd start by checking a couple typical causes for collision issues:


- Rope is not stretched in a way that gaps open in between particles, as other objects will easily pass trough the gaps. If it's necessary to stretch it pass this point, using surface collisions might help.


- Solver substeps/iterations are sufficiently high for the simulation to come close to converging. If the solver stops the simulation before it's close to converging on a solution, constraints won't be met and the simulation won't behave as expected. The manual contains an in-depth explanation of this that might help: http://obi.virtualmethodstudio.com/manua...gence.html


Even if you could modify the impulse before the simulation has taken place (which you currently can't, since contact callbacks report the solver's solution after it's been applied), modifying stickImpulse would make things worse as it pushes the particles towards the surface they're colliding against, so any trouble staying out of the surface would be exacerbated. What you'd want in this case is the exact opposite: modifying the normal impulse to keep particles out of the colliding surface.

kind regards,

Thank you for the detailed answer
The rope is already using surface based collision
I tried to raise and lower various parameters, like the substeps, the iterations of the surface collision,the max depenetration margin.. but still it breaks when i stretch it, even more than before when i raised the substep parameter (now is 8 before it was 22)