get_attached_geometry Crashes Python Kernel

[Aaron Henry]

Hello,
I am currently trying to print the scale factors of a scaled model through the Python API. I have attempted to run the following script:

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model = osim.Model(scaled_model_path)
body = model.getBodySet().get(0)
geometry = body.get_attached_geometry(0)
factors = geometry.get_scale_factors()

The python kernel dies every time I call the get_attached_geometry() method. I have not had any issues with calling other methods from the body object and can manually open the scaled model to view the scale factors, so I know there is no issue with the model file.

[Ayman Habib]

Hi Aaron,

The call

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body.get_attached_geometry(0)

assumes that there are actually some Geometry items attached to the body and that you're getting the first one of them. If that's not the case you're indexing out of bounds and a crash is not surprising. I would not call get_attached_geometry(n) unless you verify first that you have (n+1) attached pieces of Geometry due to zero indexing (e.g. using

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getProperty_attached_geometry().size()

)

Hope this helps,
-Ayman

[Aaron Henry]

Ayman thanks for the reply. I am assuming you mean getPropertyByName('attached_geometry')? I used that function to check the size and it did return 0 which is likely why my kernel was crashing. I can confirm that each body has at least 1 attached geometry in the .osim file, but how would I call the attached geometry for bodies that only have 1 attached geometry and not n+1? Would this require me to first go through the components, then the physical offset frame and finally the attached geometry associated with that frame?
Thanks