[nhnhan]

It is a wonderful idea. I won’t miss it
Thank you SOFA teams and keep it on
Best regards,
Nhan

[nhnhan]

Hi @sergiopm23, sorry for the late response. I suggest you to try the rigidify function in STLIB plugin. I have not tried it but it looks like the thing you need. If you find it hard to use I believe there will be many guys out there to help you. Good luck
best,

[nhnhan]

Dear @sergiopm23, from your scene file, I guess the tendon component should be a rigid body right? In this case, you might want to change the value of ‘template’ field of MechanicalObject from Vec3d to Rigid3d. Hope this help

[nhnhan]

hi @hugo,
I have tried to extract the force (or more specifically total force in the contact area) caused by the collision between two collision models using Lagrange Multipliers. As far as I understand from your guidance and from SOFA code of ‘constraintsolver’ and ‘mechanicalObject’ components, the constraint forces in ‘constraintsolver’ are lambda and the constraint values provided in ‘mechanicalmodel’ actually belong to matrix H in this equation: A*deltav=dt*H_transpose*lambda. So if it is true, I suppose that constraint values are results of the partial derivation calculation of holonomic/non-holonomic constraints with respect to xi. Then, from your above response, what do you mean by calculating derivation of H as shown below:
F_collis[node] += Deriv( Hx Hy Hz) * lambda[i]
Deriv( Hx Hy Hz) is derivation of H with respect to time t?
Furthermore, could you suggest to me a way do this calculation in SOFA code or maybe in Sofapython? thank you for your support
best regards,
Nhan

[nhnhan]

Dear @jnbrunet,
I just wonder that could I able to execute the “reset scene” function using sofapython 2.7?? otherwise, I want to recover the shape of a deformed object back to the original one after the end of the interaction. Is there any other solution for this purpose?
Appreciate for any help
Nhan

[nhnhan]

Hi everyone,
I am having the same problem as described in this post. My scene is quite a little bit different which can be reviewed through this link. To summarize it, I have a flexible tube that is pneumatically actuated to certain pressure Q using SurfacePressureConstraint and an object (the finger in this scene) moves forward to make interaction with the tube. Things seem fine until the collision occurs in the early state (with a small number of contact nodes), the tube appears to be “exploded” and then the simulation is crashed. I can say that the tube was not deformed as expected when making contact with the object. Also, I got this warning in the terminal

[WARNING] [GraphScatterredType] set an element is not supported in MultiVector

I have followed all suggestions in this post but nothing works. Otherwise, I also have some minor problem:
1. When you load this scene, there will be error message said:

[ERROR]   [TetrahedronSetTopologyContainer(topology)] Cannot find edge 0 [167, 0] in triangle 0
[ERROR]   [TetrahedronSetTopologyContainer(topology)] Cannot find edge 0 [167, 0] in triangle 0
[WARNING] [TetrahedronSetTopologyContainer(topology)] TrianglesAroundEdge buffer can't be created as EdgesInTriangle buffer creation failed.
[ERROR]   [TetrahedronSetTopologyContainer(topology)] Cannot find triangle 0 [335, 337, 205] in tetrahedron 0
[WARNING] [TetrahedronSetTopologyContainer(topology)]  In getTetrahedronArray, cannot find edge for tetrahedron 0and edge 0
[ERROR]   [TetrahedronSetTopologyContainer(topology)] Cannot find triangle 0 [335, 337, 205] in tetrahedron 0
[WARNING] [TetrahedronSetTopologyContainer(topology)] TetrahedraAroundTriangle buffer can't be created as trianglesInTetrahedron buffer creation failed.

I tried to reopen the mesh file (.vtk) by using gmsh and it seems okay. So, i don’t understand why this error popped out.
2. When I change the inner pressure value, the tube is supposed to be expanded evenly in all direction but it is not (in my opinion) and the model is weirdly shaking

Hope to hear your thought about this issue, and any help is deeply appreciated. Thank you

[nhnhan]

Dear @Hugo, @faichele,
I had the same problem as mentioned by @shuo, and I would like to update my progress regarding this issue. I guess this error might be because the suggested version of the Softrobot plugin in . I changed to the newest version from and this error was disappeared. However, new errors arose related to ZyRosconnecter plugin during configuration in CMake as described below:
`Adding plugin ZyROSConnector
Adding SofaROSConnector plugins.
CMake Error at SofaKernel/SofaFramework/SofaMacrosInstall.cmake:157 (message):
Missing parameter PACKAGE_NAME.
Call Stack (most recent call first):
applications/plugins/SofaROSConnector/ZySOFAControllers/CMakeLists.txt:37 (sofa_create_package)

CMake Error at SofaKernel/SofaFramework/SofaMacrosInstall.cmake:157 (message):
Missing parameter PACKAGE_VERSION.
Call Stack (most recent call first):
applications/plugins/SofaROSConnector/ZySOFAControllers/CMakeLists.txt:37 (sofa_create_package)

CMake Error at /snap/cmake/775/share/cmake-3.19/Modules/WriteBasicConfigVersionFile.cmake:43 (message):
No VERSION specified for WRITE_BASIC_CONFIG_VERSION_FILE()
Call Stack (most recent call first):
/snap/cmake/775/share/cmake-3.19/Modules/CMakePackageConfigHelpers.cmake:231 (write_basic_config_version_file)
SofaKernel/SofaFramework/SofaMacrosInstall.cmake:182 (write_basic_package_version_file)
applications/plugins/SofaROSConnector/ZySOFAControllers/CMakeLists.txt:37 (sofa_create_package)

[nhnhan]

Hi @hugo,
Thank you for your effort in connecting with the authors of these plugins. These ones are of my interest and I really want to exploit them. I have faced some errors as shown below:
#error "OpenGL headers have been moved to Sofa.GL. Therefore you will need to link against Sofa.GL if you need OpenGL (PR1649), and include <sofa/gl/DrawToolGL.h> instead of this one."

Then when I tried to include <sofa/gl/DrawToolGL.h> as recommended, another error said “there is no such file”
Hope some one can have solution or any suggestiong will also be appreciated
Nhan

[nhnhan]

Hi @bmarques,
Thank you very much for sharing your wonderful works. I have been struggling to compile these plugins to SOFA, however, they seem not to be updated for a while. Specifically, they require OpenCV 3.2 for Imageprocessing, and OpenCV 3.0 for Sofacv. I have attempted to install these packages on my computer (ubuntu 20.04 which already provides OpenCV 4.2) but not successful. I just wonder that do you have intent to upgrade these plugins to be more compatible? I personally think these plugins will be very crucial. Thank you very much.
Nhan

[nhnhan]

Dear @hugo,
I had faced the same problems as these guys mentioned above.
Regarding the issue of “Could not find ROS package”, it might be because you are using the old version of SoftRobot plugin. Using the one from https://project.inria.fr/softrobot/ might fix it. After that, you will have similar error with @roland-dreyfus, @eyadshak
Please notify us when there is progress regarding this issue. Thank you very much
Nhan

[nhnhan]

Hi @bmarques,
I’m so happy to hear that there is a plugin helping us to be able to add a fish-eye camera to SOFA. I have been doing the exact things described above, therefore, It would be nice if I can play with this plugin. However, apparently, I need to acquire an account to access gitlab.inria.fr from an Inria member. Could you please provide me one? Thank you and looking forward to your response soon.
Nhan

[nhnhan]

Dear @hugo
I have created a PR (#1745) related to my proposal. I also add an example scene and it works. Since this is my first PR as well as implementation work in SOFA, therefore, there will be a lot of things would/should be improved. Thanks in advance for any kind support or advice from SOFA dev community.
Nhan

[nhnhan]

Dear @hugo,
In fact, I have implemented the FORCE FIELDs for such types of elements and it successfully is compiled and run with SOFA. However, I know that this FF is still raw and has many things to be improved, thus it would be great if I can receive any advice or suggestion from you or any SOFA developer regarding this work in private (just for this moment). Looking forward to your response and thank you very much.
Best regards,
Nhan

[nhnhan]

Dear,
You should take the picture of the errors shown on the terminal to help us know what is your problem.

[nhnhan]

Dear, @hugo
I dowload the master version of SOfa and it works perfectly with these plugins. Thank you so much
Best,
Nhan

[nhnhan]

Dear @hugo
Thanks for your response, I have solved this issue as quite similar to your suggestion.
Best regards,
Nhan

[nhnhan]

@fsharifi135, @damien-marchaluniv-lille1-fr
Hi, sorry for the sudden contacting. I read your post in SOFA community forum which mentioned a topic that I’m interested in regarding exporting stiffness matrix. I have been trying different solutions to do such things but no significant progress occur so far. As far as I know, only HexaheronForceField exposes stiffness matrix in its data field, so that we can extract by using python scripting easily. However, for other forcefields such as tetraFEMForceField are not the case. Do you have any ideas or updates so far regarding this issue??? Thank you in advance
Best,
Nhan

[nhnhan]

Dear Hugo,
Thanks for your prompt response, I am using stable SOFA version 20.06 and STLIB version 3.0 (indicated in CMAKElists file).
Since you predict that these versions are not compatible with each other, therefore I just look up the website of softrobots plugin and it seems that this plugin is useable only for unstable version (if I’m not wrong).
And just in case it is true. Since I’m not so sure if everything else works fine with the “unstable” version, therefore, what if I build another version of SOFA (unstable one) alongside the stable one?

Hope to receive your comment. Thank you very much
Best regards,
Nhan

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