inverse kinematic problem

[abeer mohamed]

Hello all,
I just download opensim 3.1, I run the scaling uploading opensim setup file (subject01_setup_scale), then I run the inverse kinematic uploading also opensim setup file (subject_setup_IK) and this the error I received.

InverseKinematicsTool Failed: AssemblySolver::assemble() Failed: SimTK Exception thrown at Assembler.cpp:842:
Method Assembler::assemble() failed because:
Optimizer failed with message: SimTK Exception thrown at Assembler.cpp:225:
Error detected by Simbody method AssemblerSystem::objectiveFunc(): calcGoal() method of assembly condition Markers returned a negative or non-finite value -1.#IND.
(Required condition 'goalValue >= 0' was not met.)

Assembly error tolerance achieved: 0 required: 1e-006.

thanks
abeer

[jimmy d]

Abeer-
Perhaps check the marker tracking weightings to make sure they are not all set to 0.
cheers,
-james

[abeer mohamed]

Hi James
I checked the marker tracking weightings, they all were set to zero, I reset all of them. however now the Run button is disable, so there is no way to run IK.
thanks
abeer

[jimmy d]

Abeer-
it wont run if any marker is checked for tracking but isnt in the the trc file. Go through the markers and see if any are highlighted red. Uncheck all of those and you will be able to run.
-james

[abeer mohamed]

Hi James
thanks, it work now.
abeer

[shuyang han]

Hi James,

Will a gap (missing marker in certain frame) in the .trc file produce the same problem ? I am a new user. I collect data using Cortex, and export .trc file. Should I fill the gaps for the motion data prior to OpenSim ? Does OpenSim has the gap-filling function? Thank you !

Abeer-
Perhaps check the marker tracking weightings to make sure they are not all set to 0.
cheers,
-james