compute a fictitious experimental marker that you can track during IK like any other marker Thank you! I think this is what I'm trying to do, but for the moment being, whatever constraints I give to these fictitious experimental markers does not change the result of inverse kinematics, do you have ...

I want to add a constraint that the distance between 2 specific markers should be constant You can add a ConstantDistanceConstraint ( https://simtk.org/api_docs/opensim/api_docs/classOpenSim_1_1ConstantDistanceConstraint.html ) to the model. The constraint will maintain a constant distance between ...

AssemblySolver is probably what you are after; https://github.com/opensim-org/opensim-core/blob/4446724f558fb15a4fb4fd6a2dbd2df3c20f9d6a/OpenSim/Simulation/AssemblySolver.cpp Hi, When doing inverse kinematics, if I want to add a constraint that the distance between 2 specific markers should be cons...

Sorry for the late answer, I was searching for the place where this function was called. It may not be that but try to have a look at this link https://github.com/opensim-org/opensim-core/blob/4446724f558fb15a4fb4fd6a2dbd2df3c20f9d6a/OpenSim/Simulation/InverseKinematicsSolver.cpp Yanis Hi Yanis, Th...

y_ammouche wrote: Opensim will try to find the set of coordinates q that minimize the sum of the squared difference between the position of the virtual marker (function of q) and the position of the real markers specified on the trc file.

Where is this functionality realised in the source code ?

Hi Yanis, I have a model which contains 24 markers, and I added 2 markers on the scapula, 100 markers on the thorax, but I don't have their real positions in .trc, so I added 102*3 NaN in the .trc file, to make sure that IK works. Apart from doing the normal IK for the 24 markers, I want to ensure t...

Hello, What kind of constraints do you want to use ? Yanis. Hello, I am doing research on scapula, i add 2 markers on the scapula, and want to make sure that these 2 markers stay as close as possible to the thorax, so i create 100 markers on the thorax, for each frame, i try to find the minimun dis...

Hello,

I am currently working on InverseKinematics, I want to add a constraint when calculating marker errors, but I cannot find the objectiveFunction of InverseKinematics, can someone help me?

Thank you

Ye YUAN

mitkof6 wrote:

Code: Select all

const OpenSim::Ground& ground = model.getGround();
const OpenSim::Body& scapula = bodyset.get("scapula");

Last question
How can I transforme OpenSim::Body to SimTK::Body?

You can get a body form the BodySet by name e.g. bodySet.get("scapula"), if the body exists. Thank you for your answer! I tried all these two possible methodes: toBody = markerSet[1].getBody(); toBody = bodyset.get("scapula"); and none of them work, while I can use bodyset[1].getName(); and markerS...