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+--- Thread: Add Constraint problems (/thread-2588.html)
Add Constraint problems - datzme - 22-11-2020
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
RE: Add Constraint problems - josemendez - 23-11-2020
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:
(22-11-2020, 07:01 PM)datzme Wrote: 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:
Quote:Vector3 hit = boxCollider.transform.InverseTransformPoint(rope.solver.transform.TransformPoint(contact.point)); // solver to collider space.
(22-11-2020, 07:01 PM)datzme Wrote: 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/tutorials/pinconstraints.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.