Help Collision Problem

[onurbas]

Hi there,

I will be glad to have your guide for my Obi Rope issue:

You can see that the ropes are actively interacting with each other from the image below,



But when i purchased and downloaded your assets’ latest version and run it in a new Unity project, that scene is not working like in the video. The ropes are not interacting with each other.

Will be really happy if you can let me know how can i fix this!

Note: ***If the new version has this kind of issues, can you please let me know the correct unity version to try and share me the version 3.1

[josemendez]

Hi there,

The image you're referring to is not visible. I'm guessing that you're referring to a video of the freight lift where the ropes collide with each other. The solution to make ropes collide with each other is to set them to use different phases, as explained in the manual:
http://obi.virtualmethodstudio.com/tutor...sions.html

Also, do not forget to enable particle collision constraints globally, in the ObiSolver component.

[onurbas]

I Add images and trying change phases

---

Rope blueprints using same references can't change.I create new blueprints and set ropes collision was active but not effective as in the video.

[pavelpipkin]

[b][b]josemendez[/b][/b]  Hello.

I have a similar problem.

I'm making the game where ropes should be entangled between each other, and player should untangle them. So I need ropes which will not pass through each other in any way.
It looks like this:



Is this possible with obi ropes?
What I should add to obi Rope game object? Obi collider (with box collider or other?). Should I add obi rigid body to ropes?
I tried with 2 ropes with different blueprints, different phases for paths points and obi collider settigns, they are under the same obi solver and collision constraint is on. result the same: ropes passing through each other. There is some interaction, they affect each other on collision, but passed throug any way. 
On Lift example they passing every time (can't get results with a knot, like on that video above). on RopeAndJoints example they passing from time to time (but if I set ball to kinematic, so it will not move, they always pass through each other).

Using Unity 2019.4.6f1 and obi Ropes 5.3

For now I just want to know is this task really possible with obi ropes or I wasting time trying to do impossible.
But if you provide answers to other questions, configuration screenshots or even working example of two (or more) entangled  (for any version of unity, I will download and check) I will be really grateful.

[pavelpipkin]

I found a problem. When ropes not really stretched - everythin is ok, they are getting entangled quite well. But when some of them stretches, it creates gap between particles and ropes untangles (rope go through other rope) through this spaces between particles. Sorry for noob quesion, but how I can fix this? Ideal solution I think will be when new particles added automatically on stretching, maybe there is some option for this in settings? Other solution - some option to don't allow stretch rope engough so this gaps will be created. I don't think I neet really stretchy ropes, 50% for my purposes will be quite enough (though it's still limitation and first option I like more).

[josemendez]

I found a problem. When ropes not really stretched - everythin is ok, they are getting entangled quite well. But when some of them stretches, it creates gap between particles and ropes untangles (rope go through other rope) through this spaces between particles. Sorry for noob quesion, but how I can fix this? Ideal solution I think will be when new particles added automatically on stretching, maybe there is some option for this in settings? Other solution - some option to don't allow stretch rope engough so this gaps will be created. I don't think I neet really stretchy ropes, 50% for my purposes will be quite enough (though it's still limitation and first option I like more).

Hi there,

This is a limitation of particle-based engines: collision detection is also particle-based.
Creating new particles in between existing ones at runtime is not possible, since constraints are pre-batched for efficient parallel solving and adding new particles would break this batching and force a re-batch, causing performance problems.

Using more substeps in the ObiFixedUpdater will improve convergence, making the rope less stretchy. Also, using a rope blueprint resolution of 1 will make particles overlap each other, giving you roughly 50% stretching room while keeping good contact sampling.

[pavelpipkin]

Thanks for your answer. Already set the resolution to 1, but will play with substeps. Anyway, I will make prototype with obi ropes, just to check, but even a small chance for such situation is quite a blocker.  Not your problem of course, and no refund needed.

Maybe, as professional in this area you can recommend some other lib which can work for my goals? or some hints for best approach to implement this? I'm quite new in Unity 3D (but have quite a lot of experience as programmer). Heard about solution with rigid bodies and joints, but don't like how they look. Olso heard about using unity cloth as cylinder, but still not figured out how to do it. With your recommendation to where to look and which approach is better for my goal (quite realistic ropes and their entanglement), you can save me a lot of time on research.