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Dear Experts,

I added a new bodyset to my model and the geometery was in .stl format.
When I open my model in OpenSim 3.3 everything is correct but in OpenSim 4.0 GUI, that new geometery is broken.
the first image is OpenSim 3.3 GUI and the second one is v. 4.0
Any help would be greatly appreciated.
Cheers

Hello Mohammad,

OpenSim 3.3 used vtk to parse STL files so it was able to handle a variety of files, in version 4.0 we dropped vtk since we're using a different tool/package for visualization, instead we use simbody's native STL parsers. These seem to handle a smaller subset of STL files, in particular, if the file contains more than one solid then it's likely not going to work. In this case I'd suggest you split the solid into different STL files and include them individually. While this may have been documented in 4.0 release notes, we understand the inconvenience and have ideas to fix the issue. Please file a bug using the bug reporting feature in the software and attach the stl file so that the issue is tracked and prioritized.

Best regards,
-Ayman

Dear Ayman,

Many thanks for your reply.
I split my 3d model in different solids and fortunately, the visualizer showed the geometries, correctly.

I want to ask a new query regarding the axes of geometries. For example in the femur body, the axis is located in the femoral head.
is it possible to change the axis location of a geometry? in my 3d model, the axis is located in the middle of the body (somewhere near the body mass) and I want to set it in the most proximal part of that (like tibia or femur).

Your help would be greatly appreciated.

Cheers

Dear Mohammad,

In most cases, in our examples, the geometry mesh file is attached directly to the Body frame, however the model format allows for the introduction of an offset between the the Geometry frame and the body frame. In version 3.3 the rotations and translations were exposed in the GUI to allow you to move the Geometry w.r.t. the Body using the property editor in the lower left panel of the application, in version 4.0 this is also possible by defining a new Frame with the desired transform (translation/rotation) and then attaching the mesh to it.

Hope this helps,
-Ayman

Dear Ayman,

I appreciate your help.
My problem was solved completely.

Cheers