simtk.org

Hi,

I am a novice in opensim but have been using visual3D (v3d) for quite some time. I am exploring opensim via v3d export function. When using v3d demo files, I can run RRA and CMC. However, when I use my data, it always crashes when running RRA. That naturally leads one to deduce something is wrong with my data or model. But I cannot find anything wrong. In any case, it always crashes instead of generating some form of error.

I hope someone can help me.

Attached are the demo and my data files and the crash log.

Regards,
Bernard Liew

Hi Benard,

Thanks for sending those zips through. It was much easier to diagnose with the files.

From the zip containing your data, I opened the model (Visual3d_simbody_adjusted.osim) and loaded the motion (Visual3d_SIMM_input.mot). Immediately, I could tell that the motion is incorrect. The kinematics look really screwy and the forces are not correct.

To begin with, the max/min for pelvis rotation is being exceeded and causing the sign flip. The trunk angle and pelvis tilt are also way off. The biggest issue is the location of the GRF with respect to the foot. The GRF looks like it's being applied half way up the tibia!

The issue is definitely on the visual3D side. I have never used the visual3d export tool, so I can't give you much advice on what's wrong. I suggest contacting product support and see if they have some advice.

Let us know how it goes,
-James

Many thanks James for the quick reply. I will get back with them and post a reply here on the comments.

Regards,
Bernard