Help Irregular Rigidbody reactions

[SilverStanley]

Hi,
I have no idea what is going on here,
Rope has a Dynamic Obi Particle attachment, attached to a cube(Load) with obi collider and obi rigidbody, the Obi Fixed Update has 3 substeps. The solver is a copy of the Crane solver.
The physics material of the obi colliders is all High Friction. When I run the game, the load rigidbody keeps jumping all over the place.

GIF of the problem

Please help me with this.
Thanks in advance

[josemendez]

Hi,
I have no idea what is going on here,
Rope has a Dynamic Obi Particle attachment, attached to a cube(Load) with obi collider and obi rigidbody, the Obi Fixed Update has 3 substeps. The solver is a copy of the Crane solver.
The physics material of the obi colliders is all High Friction. When I run the game, the load rigidbody keeps jumping all over the place.

GIF of the problem

Please help me with this.
Thanks in advance

Hi there!

1.- Since you're using both substepping and rigidbody interaction, make sure you've enabled the "substep Unity physics" checkbox in the updater, as per the manual:
http://obi.virtualmethodstudio.com/tutor...aters.html

Substep Unity physics

Enable this when using more than 1 substep, and requiring accurate interaction with Unity rigidbodies (via collisions or dynamic attachments).

If you don't, Unity and Obi will update out of sync with each other and cause all sorts of instabilities since you're substepping particle physics but not rigidbody physics.

2.- Make sure you haven't attached the rope inside or very close to the collider, if the rope is set to collide with the rope as well. In this case you need to deactivate collisions between the rope and the collider, as explained here:
http://obi.virtualmethodstudio.com/tutor...aints.html

Easiest thing to do is set the collider's phase to 1: the same as the rope particle's by default.

Attaching a rope inside a collider with which it has to collide results in an unsolvable situation: the rope can't be simultaneously inside and outside the collider. This manifests as jittering, as the engine tries to solve a situation that can't possibly be solved.

[SilverStanley]

Hi there!

1.- Since you're using both substepping and rigidbody interaction, make sure you've enabled the "substep Unity physics" checkbox in the updater, as per the manual:
http://obi.virtualmethodstudio.com/tutor...aters.html


If you don't, Unity and Obi will update out of sync with each other and cause all sorts of instabilities since you're substepping particle physics but not rigidbody physics.

2.- Make sure you haven't attached the rope inside or very close to the collider, if the rope is set to collide with the rope as well. In this case you need to deactivate collisions between the rope and the collider, as explained here:
http://obi.virtualmethodstudio.com/tutor...aints.html

Easiest thing to do is set the collider's phase to 1: the same as the rope particle's by default.

Attaching a rope inside a collider with which it has to collide results in an unsolvable situation: the rope can't be simultaneously inside and outside the collider. This manifests as jittering, as the engine tries to solve a situation that can't possibly be solved.

Thanks for the response Jose.

It is working like a charm now.

[josemendez]

You're welcome! let me know if I can be of further help.