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 error or warning at all.
- If I use another joint like Weld, Pin of Slider, everything works just fine.
- Just as an extra test, when using a Freejoint the simulator crashes.
Code: Select all
ForwardTool::run() caught an exception: SimTK Exception thrown at Integrator.cpp:431: Integrator initialization failed apparently because: SimTK Exception thrown at SmallMatrixMixed.h:878: Error detected by Simbody method lapackInverse(Mat<>): Matrix is singular so can't be inverted (Lapack getrf info=2). (Required condition 'info==0' was not met.)
- A Customjoint with the same behavior as a Balljoint has the same probem.
Here a screenshot of the model. The single upperarm in the model that is added as the latest has the BallJoint that gives me trouble.
The model actually is very straightforward. What could I be doing wrong?
Thanks in advance, Sietse