Add Constraint problems

[datzme]

I have some problems with constraints.

This is what im trying to do:


https://i.imgur.com/uMuY596.gif

This is the code


                            var pinConstraints = rope.GetConstraintsByType(Oni.ConstraintType.Pin) as ObiConstraints<ObiPinConstraintsBatch>;

                            pinConstraints.Clear();
                            Vector3 hit = rope.transform.InverseTransformPoint(contact.point); // this didnt work at all.
                 
                            var batch = new ObiPinConstraintsBatch();                                    // cheating with the pos, dont know how to get the correct position.
                            batch.AddConstraint(rope.solverIndices[contact.particle], boxCollider, new Vector3(-0.5f,-0.25f,0), Quaternion.identity,0,0,float.PositiveInfinity); 

                            batch.activeConstraintCount = 1;
                            boxCollider.Phase = 1;
                           
                            pinConstraints.AddBatch(batch);

                            rope.SetConstraintsDirty(Oni.ConstraintType.Pin);

:
what im trying to do is to make it stick to the box smooth, and then i want to be able to drag the box around and rope follow smoothly.

I also tried to use the Grab script, it looks good, but it will go crazy kinda fast:
https://i.imgur.com/zogiZZZ.gif

[josemendez]

As stated in the manual, the solver performs all  simulation in local space. All contact, particle, and constraint values are expressed in the solver's local space. This:

Vector3 hit = rope.transform.InverseTransformPoint(contact.point); // this didnt work at all.

Will transform a world space position to the rope's local frame. Neither the origin or the destination vector spaces are correct. It should be:

Vector3 hit = boxCollider.transform.InverseTransformPoint(rope.solver.transform.TransformPoint(contact.point)); // solver to collider space.

I also tried to use the Grab script, it looks good, but it will go crazy kinda fast:
https://i.imgur.com/zogiZZZ.gif

I'll assume the box is a rigidbody: your issue is that you're attaching the rope too close to it (or inside of it), so particles overlap its geometry. The result is that attachment and collisions cause a force feedback loop, since neither can be solved. This situation, along with its solution, is described in the manual. See:
http://obi.virtualmethodstudio.com/tutor...aints.html

The grab script is designed with kinematic rigidbodies or simple colliders in mind. In this case, simply attaching the rope slightly offsetted from the collider surface would suffice.