I now understand that it is a challenge to use CMC in the fast target mode, especially when using contact forces.
Therefore I switched to the slow target mode, this works better.
But alas, I now suffer from all kinds of instability. I with post a new message to describe it.

To answer my own question: it was not too difficult in the end and I did the following. I created a clone of ElasticFoundationFource.cpp and *Impl.h. Then changed the function processContact as follows. First calculated the angle in the XZ plane between de X-axis and the direction of the speed: cons...

Hello List, I reduced the model as much a possible, but the problem still exists! There are now only 6 joints and 7 actuators. Not much more than an upper- and lower-leg connected to one fixed and one movable box, see the picture. The code can be found in https://github.com/SietseAchterop/Rowing-sim...

Hello List, I am looking for some guidance in creating a new friction-force model. I intend to create a variant of the ElasticFoundationForce that does what I need. Friction occurs between two bodies. In my usecase one of the bodies is special in that the friction depends upon the direction of the f...

Hello List, I created a model of a "rower" in a "rowing boat". After using the CMC-tool with a simpler example (3 joints) I now am trying to get it to work with this more complicated example (26 joints/33 actuators), but the tool is failing/hanging/crashing in the first step with the following (open...

Thanks!

Hello List, I installed opensim from source on a few Ubuntu 20.04 and Debian 11.1 machines. I used the ad hoc script below, derived from the version in github. There are 3 issues that I want to mention. == 1 == Very recently some libraries are not properly placed in the final opensim directory. This...

Hello List, When doing forward dynamics and inverse kinematics it seems that the range restriction is not honored. For example <Coordinate name="footangle"> <range>0.200 1.57</range> </Coordinate> I thought that the purpose of a range is to restrict the possible values of the coordinate. Am I missin...

I am not too familiar with opensim, but I think you have to select the body in the Navigator, then change the mass in the properties and save the model.

Sorry, stupid counting error in making the mesh. Forget it.