Help Mocking a bundle of cables

[griswold]

Hi Adam,

Control points are expressed in the rope's local space. If you move a control point to the rope's local zero, and then move the rope around, the control point position and the rope position in world space will be the same (hope this makes sense!).

Latest Obi version (6.4) exposes numerical position and tangent fields for each control point, which means you can precisely place blueprint control points instead of eyeballing them or tweaking by hand (see: http://obi.virtualmethodstudio.com/forum...-3297.html). If this is not enough, maybe a writing a procedural placement system would be a better approach? This would allow you to set points programmatically.


I suggested Bill to use skeletons (or more generally, linear blend skinning) as a way to cheaply simulate and render a bunch of cables that are tightly bundled together. Since each individual cable won't have much impact on overall behavior of the whole bundle, it's simpler to approximate the entire thing as a very thick cable. I don't know if this would be beneficial in your case, as it depends on how "rogue" each cable can get.


Constraint "battles" (if the behavior you're getting is really that) are always caused by constraints trying to enforce mutually incompatible conditions. When dealing with attachments this is almost always due to a particle that's attached inside a collider: the collider tries to push the particle outside, and the attachment tries to place it back inside. Filtering out collisions is the way to go in these cases.

If you could give more details about your setup I will be able to provide further guidance. let me know how can I help!

kind regards,

Hi Jose,

Thank you! yes that makes sense about the control points.  I am trying to create an accurate to physics simulation, realtime is not a requirement but would be a bonus if possible.  I attached a picture of the CAD model of the cables, lanyards, and connectors.  The two groups of connector ends will be moving relative to each other and at a specified but variable distance the lanyards will pull off the connectors, the designers are interested in any re-contact between those disconnected connectors and any of the surrounding structure. 

I have tried to model the cable as a simple rod, and attached the lower left end to the connector with a static particle attachment, and then used a dynamic particle attachment to the connector on the upper right.  I am struggling to configure the rod/attachment because when that connector is detached (rigidbody isKinematic set to false) I am getting wild reactions from the rod.  I have made sure that there is no conflict with the connector collider and the particle positions and used accurate widths for the rod and mass for the connector. 

Can you recommend an approach?

Thanks,
Adam