I found out that what a "facet normal" is and that not all normal where pointing outward from the brick. I made it so that, looking from the inside, following the 3 vertices of a triangle, I now am going clockwise and therefore the normal is pointing outward. But there still is an error: Traceback (...

Hello list, Trying to create an stl-file to be used in ContactMesh, but my python script ends with: Traceback (most recent call last): File "/home/sietse/Roeien/Modelling/OpenSim/MyCode/Pusher/pusher.py", line 170, in <module> blad = osim.ContactMesh('brick.stl', File "/home/sietse/Software/OpenSim/...

Hello list, I seem to misunderstand the slow optimization setting, because it does not seem to work. I created a simple model using 3 bodies and 3 Pinjoints, all code and a few video's to show the working of controlling the model using fast or slow optimization. The code can be found here here . leg...

I understand that the coordinates/positions in a marker file are with respect to the ground frame, correct? In my use case, a simulation of a rower in a boat, I am interested in the speed of the rowing wrt to the ground frame. To control the rower I want to describe its motion using a marker file th...

Yes, i gave all bodies a non-zero inertia and the original model is working fine now.
Now I can go to the next step, adding some constraints to complete this first version of the boat.
Thanks!

It does. Thanks!

I simplified the model and the problem still persists! There now only is ONE body and ONE joint. The complete code is: import opensim as osim import math pi = math.pi bbaan = osim.Model() bbaan.setName("BootBaan") bbaan.setGravity(osim.Vec3(0, -9.90665, 0)) upperal = osim.Body("Upper_Arm_Left", 1, o...

The reason the ContactMesh didn't work was that it needs the ElasticFoundationForce instead of the HuntCrossleyForce.

Thanks for the idea.
But the friction should also dependent upon the Z coordinate. The friction plane has to be lifted off from the "ground/water" and then there should be no friction at all. We'll see.

Hello, Created a model, 20 bodies, 20 joints, all very straightforward. Until now simulations work nicely. But when adding the next body and (for the first time) BallJoint, the simulation does not work properly. In the very first step of the simulation the model is vanished completely! There is NO e...