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obi shape - Raymond - 31-07-2023

I am using obirope 6.4 now,
I want to change the head and tail bend angle of the rope, and keep the bend while moving.
At the beginning, I used static attachment and found that the effect was wrong. Later, when I added obicollider on the head and tail nodes and set dynamic, the effect was still wrong. Once moved, the head and tail did not keep the original bending, but random The shaking, the following is the effect picture after prohibition and movement. I want to keep the curved shape of the head and tail when it is still after moving.
This problem does not occur when I use the particlehandle component of 4.1 I hope to get a solution


RE: obi shape - josemendez - 31-07-2023

(31-07-2023, 10:14 AM)Raymond Wrote: I am using obirope 6.4 now,
I want to change the head and tail bend angle of the rope, and keep the bend while moving.
At the beginning, I used static attachment and found that the effect was wrong.

Hi!

Constraining the position of a single particle will allow the rope to freely rotate around it, since an infinite number of lines pass trough a single point in space. Only one line passes trough two points, so you'll need to constrain two particles.

You need to add two particle attachments at each end, one to the very last particle and a second one to the previous particle. This will force a specific orientation on the rope.

Optionally you can use rods instead of ropes, which use oriented particles and can constrain orientation using a single attachment.

(31-07-2023, 10:14 AM)Raymond Wrote: Later, when I added obicollider on the head and tail nodes and set dynamic, the effect was still wrong. Once moved, the head and tail did not keep the original bending, but random The shaking, the following is the effect picture after prohibition and movement.

Make sure your collider is not colliding against the attached particles. If they're too close to it or intersecting, constraint fighting will occur as described in the manual, along with its solution - properly setting up collision filters.


RE: obi shape - Raymond - 31-07-2023

(31-07-2023, 10:39 AM)josemendez Wrote: Hi!

Constraining the position of a single particle will allow the rope to freely rotate around it, since an infinite number of lines pass trough a single point in space. Only one line passes trough two points, so you'll need to constrain two particles.

You need to add two particle attachments at each end, one to the very last particle and a second one to the previous particle. This will force a specific orientation on the rope.

Optionally you can use rods instead of ropes, which use oriented particles and can constrain orientation using a single attachment.


Make sure your collider is not colliding against the attached particles. If they're too close to it or intersecting, constraint fighting will occur as described in the manual, along with its solution - properly setting up collision filters.
Thanks a lot ,Adding tow Attachments at the end works well!


RE: obi shape - Raymond - 01-08-2023

There is also a problem: how to make the rope softer, my rope looks hard, like wire
the first is which I used 4.1 before, theĀ other one is 6.4


RE: obi shape - josemendez - 01-08-2023

(01-08-2023, 04:43 AM)Raymond Wrote: There is also a problem: how to make the rope softer, my rope looks hard, like wire
the first is which I used 4.1 before, theĀ other one is 6.4

Can't know for sure without comparing your settings in both versions. My guess would be you should reduce the amount of substeps/iterations, you will find the substeps parameter in the ObiFixedUpdater component, and iterations in the ObiSolver component. These control overall simulation quality and maximum stiffness/hardness reachable by the solver.

See the manual for a very in-depth explanation of how the engine works internally and how substeps and iterations affect the results:
http://obi.virtualmethodstudio.com/manual/6.3/convergence.html

kind regards,