By the way, testing on a simple double pendulum, both the SimmSpline you have and the LinearFuction are equivalent, so it's likely you'll get the same behavior in your model after this change too. In case the change doesn't help, consider double checking the definitions of your coordinates to make ...

Depending on your pipeline, you might be able to use the BodyKinematics analysis. If you're working with the API, check out the outputs in the Frame class (Body inherits from Frame): https://simtk.org/api_docs/opensim/api_docs/classOpenSim_1_1Frame.html getTransformInGround() could be helpful here....

Greetings, I am trying to constraints two coordinates, let's say q1 and q2. I want this relationship q2 = -q1, however, I always end up with q2 = q1. Please look below to the code implementation: <CoordinateCouplerConstraint name="q1_q2_con"> <isEnforced>true</isEnforced> <coupled_coordinates_functi...

Hello, I am trying to use Matlab R2021a with OpenSim 4.3. Every time that I run the below code Matlab executes all the commands, and then it stops working. Any idea why this is happening? %% Matlab Script for Opensim clearvars import org.opensim.modeling.* % Import OpenSim Libraries model = Model('F...

Greetings, I would like to know if it is possible to get the spatial information of a body frame of a model during during a trajectory after applying the generalized coordinates motion to the model. What I want to do is to find the relative position and orientation of two body frames. Therefore, I n...

Hello, I am running into the same problem as BJ. It has been explained that I would need to add a PhysicalOffsetFrame on each body. I would like to know if you can share a sample code how to define those extra frames and then, how to reference them into the Welded Constraint parameter: <WeldConstrai...

Hi! I also have an issue/question about using input_transform--if you figure it out, would you be able to share? Thanks! Katie Hello Katie, Of course, however, I have not figured out how to use it yet. In the mean time, what I did was to open the files in a CAD software and from there change the or...

Hello, I would like to know if someone can help me to figure out how to apply a transformation to the mesh file that I am importing to a body in a xml file. I want this because the location of the body frame for the part is not in the right place for the geometry file. I already know what is the tra...

Hello, I am working with Opensense, I have the orientation information coming from 3 different sensors placed on the upper body of a subject (Clavicle, Humerus, and Radius). With this information I know I can compute ik, however, I would like to scale the musculoskeletal model to the dimensions of a...

Thank you very much, once I have it and it is ready I will share it!