bone files from scanned data?

[Kazutaka Takahashi]

Hi. I am wondering if we can use our scanned/segmented skeleton data imported into an opensim model. Also, what are the formats of bone and geometry files? Thank you so much in advance!

[Ayman Habib]

Hi,

For visualization purposes in the GUI you can use either .vtp (VTK Format), .stl or .obj file formats. If you're going to use the geometry for contact/collision detection then it has to be .obj file format.

There are freely available tools to convert from other formats to these, including Paraview and Meshlab.

Please let us know if you have any questions.
Good luck,
-Ayman

[César Flores]

Hello,
I acquired a contact model template from a collaborator that included an .obj mesh sphere bouncing over a ContactHalfSpace. I run forward dynamics on this model using an xml file with the input controls and a mot file with the initial state of the model. The model works very well.
When I try to replace the ball's geometry with my own is when I have trouble. I've been trying to generate my own obj files from stls using meshlab.
The .obj files that I generate are ignored by contact. They merely penetrate and fall through the half-space.
I can even replace the half-space in the original model with a copy of the original sphere .obj file and the two spheres will not penetrate each other.
Do you have an idea of what I may be doing wrong when generating my obj files? Should I worry about mesh triangle shape quality at all?
Best regards and thanks in advance,
Cesar Flores

[Ayman Habib]

Hi Cesar,

I suspect the normals in the obj files are incorrect, you may use some third party software to check that.

Please let me know what you find,
-Ayman

[César Flores]

Hi Ayman,

I used meshlab to display the face and vertex normals and they seem fine.

Could you describe, in some detail, how you produce obj files for your own work?

Thank you for your replies and best regards,

Cesar