Simbody Visualizer and OpenSim in Python

[Markus Peters]

Hello,

I'm currently working with the OpenSens interface to run simulations in OpenSim driven by IMU data. I try to change the settings of the visualiser from the 'GroundAndSky' setting to the 'SolodColor' because it always starts with this nasty setup but somehow I miss the point. I have no idea how i can change the settings from python. Anyone out there having an idea?

Best regards,

Markus

[Ayman Habib]

Hi Markus,

Looking at the code, it appears you can indeed change the visualizer background to solid color using the call to

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setBackgroundType()

. Can you clarify how you're calling it and what are you passing as input, and whether you're getting an error message back?

Best regards,
-Ayman

[Markus Peters]

Thanks Ayman for your reply,

Yes indeed I found that argument as well in the "simbody.py" file. The problem is that I don't know what I should put into the function. In the simbody.py file it is wirtten:

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setBackgroundType(self, background: "SimTK::Visualizer::BackgroundType") -> "SimTK::Visualizer &":

The error I get, when I try to change the background with:

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SolidColor = osim._simbody.SimTKVisualizer_SolidColor
osim.SimTKVisualizer.setBackgroundType(SolidColor)

is: TypeError: setBackgroundType() missing 1 required positional argument: 'background'

When I add another argument e.g. "background" the error is:
TypeError: in method 'SimTKVisualizer_setBackgroundType', argument 1 of type 'SimTK::Visualizer *'

Basically, I do not understand the term background: SimTK::Visualizer::BackgroundType

Best regards

Markus

[Ayman Habib]

Hi Markus,

You can call

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setBackgroundTypeByInt

instead so you don't have to define an object/instance of type Background as suggested. The tricky part is that you get access to the visualizer only after it has been created so it's not clear when the change takes effect.

If that doesn't seem to work please open an issue/bug-report and we'll see what it takes to expose/feed parameters to the visualizer creation functionality.

Best regards,
-Ayman