Search found 2248 matches

by Ayman Habib
Tue Apr 15, 2008 9:37 am
Forum: OpenSim
Topic: animating ground forces and muscle forces
Replies: 4
Views: 819

RE: animating ground forces and muscle forces

<t>Hi Tim, <br/> <br/> It looks like the code treats files made up of states as a special case for efficiency reasons so other user objects can't be added to them. I'll look into fixing this but please go ahead and file a bug so that it doesn't fall thru the cracks and you get notified when it's fix...
by Ayman Habib
Mon Apr 14, 2008 12:35 pm
Forum: OpenSim
Topic: Muscle-actuated simulation error
Replies: 4
Views: 1092

RE: Muscle-actuated simulation error

<t>Hi Jon, <br/> <br/> It's great that you were able to run CMC and Forward to get muscle excitations. <br/> <br/> Forward runs in Open-loop (there's no feedback to tell the model to adjust if it's off its originally tracked motion). Arbitrary muscle excitations will definitely make for erratic mode...
by Ayman Habib
Thu Apr 10, 2008 12:54 am
Forum: OpenSim
Topic: Change the base segment in OpenSim file
Replies: 7
Views: 1230

RE: Change the base segment in OpenSim file

<t>Hi Alessandra,<br/> <br/> The base segment is implied from the topology as a segment that's connected by a joint to the ground/world. You can rearrange your model (osim file) so a different segment is connected to ground/world, this will be your new base segment.<br/> <br/> Hope this helps,<br/> ...
by Ayman Habib
Tue Apr 08, 2008 8:31 am
Forum: OpenSim
Topic: Foot model
Replies: 15
Views: 2440

RE: Foot model

<t>Dan, <br/> <br/> Yes, CMC applies these torques along with ground reaction forces. <br/> <br/> Typically, the first set corresponds to the ground reaction forces, torques, and center of pressure for the right foot, while the second set corresponds to the analogous data for the left foot.<br/> <br...
by Ayman Habib
Tue Apr 08, 2008 8:24 am
Forum: OpenSim
Topic: Pulling in-motion muscle-tendon lengths out
Replies: 2
Views: 609

RE: Pulling in-motion muscle-tendon lengths o

<t>Hi Dan, <br/> <br/> That's indeed the case. You can plot muscle lengths (and all other buit-in quantities) during a motion by picking the motion/time for X quantity, muscle-length for Y and the muscle(s) you care about for muscle-names.<br/> <br/> We will release a User's guide that will detail a...
by Ayman Habib
Fri Apr 04, 2008 10:09 am
Forum: OpenSim
Topic: Upper extremity model and markers ?
Replies: 9
Views: 2588

RE: Upper extremity model and markers ?

<t>Dear Kazutaka, <br/> <br/> The only way to combine models as of now is to edit the XML files and manually merge corresponding XML elements (e.g. <ActuatorSet>, <DynamicsEngine>, ..) in both models. <br/> <br/> This is an error prone process, and we hope to address it in the near future..<br/> <br...
by Ayman Habib
Fri Apr 04, 2008 9:56 am
Forum: OpenSim
Topic: Foot model
Replies: 15
Views: 2440

RE: Foot model

<t>Hi Christopher,<br/> <br/> When running IK (either for marker placement or for proper IK) you can have marker trajectories only or you might also have some "guess" for coordinate values as well (obtained from the motion capture system). If you have the latter, it helps the IK solver converge fast...
by Ayman Habib
Fri Mar 28, 2008 9:15 am
Forum: OpenSim
Topic: Foot model
Replies: 15
Views: 2440

RE: Foot model

<t>Thanks Daniel for the response. <br/> <br/> Some more info below<br/> <br/> 1. We don't have graphical editing of markers yet so you'll need to modify the coordinates manually in the XML file. (A possible hack is to make a muscle point at the position of the marker and use graphical editing to po...
by Ayman Habib
Tue Mar 18, 2008 4:26 pm
Forum: OpenSim
Topic: Inverse Dynamics on Upper Limbs
Replies: 7
Views: 1824

RE: Inverse Dynamics on Upper Limbs

<t>Hi all, <br/> <br/> I investigated the crash and that was caused by joints whose name starts with a number (e.g. 2MCP). If you change these names in SIMM or in the file so that they don't begin with a number, the crash will be fixed. The fix for that will go into next release.<br/> <br/> A more i...
by Ayman Habib
Tue Mar 18, 2008 10:24 am
Forum: OpenSim
Topic: Inverse Dynamics on Upper Limbs
Replies: 7
Views: 1824

RE: Inverse Dynamics on Upper Limbs

Hi Istvan,

Can you send us the .osim file you're using? Without that it's impossible to track down the bug.

Sorry for the delay,
-Ayman