Page 1 of 1

Application point of elastic foundation forces

Posted: Mon Mar 07, 2022 1:27 pm
by giorgiod
Hi all,

I have been trying to use contact meshes in lower limb models to estimate bone-to-bone and bone-to-ground contact.
Specifically, as I have access to medical imaging data, I am implementing ElasticFoundationForces (as shown in the AddCustomFeet example).

While I have no problems in getting when (in time or coordinates combination) any contact occurs, I seem unable to identify where this happens (i.e., on which node/face of the contact meshes). Are there any ways in OpenSim to extract such information (perhaps exploiting the ForceReporter or other tools)?

I would really appreaciate any help on this!

Cheers,
Giorgio

Re: Application point of elastic foundation forces

Posted: Tue Mar 08, 2022 5:12 pm
by ongcf
Unfortunately, I'm not aware of a way to get this from the OpenSim side of things (see ElasticFoundationForce implementation)

OpenSim uses Simbody to do a bunch of the calculations. You can see some of the available methods in the Simbody repo here. This may need some tweaks to your code on the C++ level, however.

Re: Application point of elastic foundation forces

Posted: Wed Mar 09, 2022 1:11 am
by giorgiod
Thanks as always Carmichael!

That's a pity, though.
Are you aware of any ways to detect mesh-to-mesh collisions in OpenSim?

Cheers,
Giorgio