[AnoushS]

Hi @Hugo;

Thanks for the response, I am looking at the documentation for BoxROI and see that I can do this now. I am trying to get it to work but it does not seem to be working properly for me using python. Could you provide an example or somewhere that I can find an implementation of this so I can figure out how to use it?

Thanks,
Anoush

[AnoushS]

Hi @Hugo;

Thank you for your response, you are correct, each mesh has a different shape and the points are not at the same location. I tried to use attach constraint but because the points are not exact, the motion is very unstable.

I am trying to define heterogenous values for the stiffness using the tetrahedromFEMForceField. The issue now is, I cant seem to use the ROI functions to determine which parts of the mesh to redefine with a higher stiffness. I am using boxROI and tetrahedraInROI to define nodes with the new forcefields, however the BoxROI only lets me define min/max points of the box and gives little control over orientation and position. For example, I need to define a cylinder through the central axes of the actuator with a higher stiffness however I am not sure how to identify the tetrahedron in that cylinder using an ROI when defining a new force field. There is not a cylinderROI I can use if I am not mistaken.

[AnoushS]

Hi @biu,

no I have not solved it. I think the solution is to use attachconstraints when trying to combine complex meshes of different properties. My issue is that I cannot find any tutorials or guides on how to use it when writing python code (using a .pyscn file)

if anyone can provide guidance or a python tutorial/guide on how to use the attachconstraints that would help tremendously.

Thanks

[AnoushS]

Hi @Jonny,

Thank you for your response. I did see from the pneunet tutorial I could use boxROI to define a stiff layer. The issue is the areas I would like to change are not easily captured via boxes. For example, I will need to define a cylinder that is in the center of the finger of a different stiffness, thus the use of the BoxROI makes that difficult.

Do you know if there are other options to define ROIs in SOFA? If I am limited to boxROI then it would be difficult to properly define all portions of the finger. Otherwise, I will look into the attach constraints.

Thanks

[AnoushS]

Ah I see to issue is with the .igs file then. I exported to a .STEP file and it seems that a volume is visible automatically.

I can now create the mesh for the cube and import it into SOFA. Thank you for your help.

I tried quickly to create a mesh for a more complex part now, but I am getting the errors “could not recover boundary mesh: error 2” and “no elements in volume 1 2”. I think this has to do with the CAD model, most likely intersecting planes/invalid geometry however I will have to take a look deeper.

Thank you for your help, it is greatly appreciated.

[AnoushS]

Hi @sescaida;

Thank you for your help. I have attached the .igs file below.

https://drive.google.com/file/d/1-5WYJDYzGmVxQ506UyWbyh6VMp-4Oeh4/view?usp=sharing

Please let me know if you need anything else.

Thanks

[AnoushS]

I have attached my attempt at creating a mesh. I have added all faces of the cube but I cant create the volume? Any help is appreciated.

Thanks

https://docs.google.com/document/d/1nvhvPTeiduKkqLlAyT386MyHLBFA00aLP-_bgDYynB4/edit?usp=sharing

[AnoushS]

Hello all.

Thank you for the help. It seems that I do not have any volumes as @sescaida mentioned. I have made a simple cube in solidworks to test the meshing software so I am sure that I have created the shape correctly, it is exporting to an STL or igs file that is the issue.

I am trying to add a volume in gmsh as @Jonny suggested. I have selected the boundaries of the cube however there is not an option to create a volume? It just says press u to under or q to abort?

How do I create a volume after selecting the boundaries?

[AnoushS]

Hi Hugo;

Thank you for your response. Can you please explain where specifically to replace the Vec3Types.h code? I have not written any code and just pulled the git repos for the plugins and sofa etc.

Thanks,
Anoush

[AnoushS]

Hi Hugo;
Thank you for your response. The full error is too long to post here, so I included a link to a document with the full error when compiling using ninja.
https://docs.google.com/document/d/14IIeJ4lXAcxEjPScFQb7LzOjyuaXXKzcYbnOR7bycY4/edit?usp=sharing
I believe there are no errors at configuration/generation phase. I also followed the following tutorial and was able to compile the “myawesomecomponents” plugin in this video
How to compile a plugin

Please let me know if you need any more information.
Thanks,
Anoush

[AnoushS]

Thank you for the response. The errors in the terminal are very long, however I included part of the error that I think is contributing to the failure to build.

[50/70] Building CXX object external_d…traint/model/AffineFunctionModel.cpp.o
FAILED: external_directories/sofa_plugins/SoftRobots/CMakeFiles/SoftRobots.dir/src/SoftRobots/component/constraint/model/AffineFunctionModel.cpp.o
/usr/bin/clang++ -DNDEBUG -DQT_CORE_LIB -DQT_NETWORK_LIB -DQT_NO_DEBUG -DSOFA_BUILD_SOFTROBOTS -DSoftRobots_EXPORTS -D_ALLOW_KEYWORD_MACROS -Dregister=”” –

(Message continues but cannot attach here)

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