Help cloth passthrough

[danazoid]

Particle connectivity is directly extracted from the mesh, since particles are visually "connected" trough mesh triangles. If there's a gap in the mesh, that's probably because your mesh has this gap too.

Also keep in mind there's no explicit differentiation between "mobile" and "attached" particles in Obi: they're the exact same kind of particles, it's just that the attached ones have their position/velocity modified by the attachment.

Thanks for the clarification. On another look it happens because of "pass through".

Here I'm assuming that the forceps are a rigidbody, and you're moving it using forces or impulses. Otherwise collisions against the cloth will of course fail at some point because the cloth is unable to prevent the forceps from moving once it's too tense: you can pull as much as you want until collision detection simply fails because cloth is unnaturally tense.

In order to have two-way interaction between the forceps and the cloth -or for any two dynamic objects to interact in a physically meaningful way, really- both must be part of the simulation.

Yes, I understand. I think not having 2-way is acceptable for me. I can restrict the movement of the forceps.




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Ok, the simulation works very well except for this pass through issue. I am very keen to get it to work.

Note you can't explicitly control the point at which collision detection fails, as it's a function of particle size vs collider size: when the pulling force is too large, larger colliders and/or larger particles will make it harder for colliders to slip between particles.

Checking my understanding here: pass through happens when the distance between cloth particles exceeds collider size?


That is why larger colliders don't pass through. Also curved colliders seem to work better, I think for the same reason.




If so, then if I am trying to model a very compliant elastic sheet, and I use a small collider to deform it, then there is a high risk that pass through once the particles separate enough? (which is in essence what my issue is)

What's the mass of the forceps rigidbody, relative to the cloth particles? Reducing the mass of the forceps or increasing the mass of the cloth will make it harder to pull it around once it's tense.

Changing the mass helps. There is less pass through, instead the cloth jitters when it is tense.


Would you mind explaining how the relative mass works on this pass through issue?