[Hugo]

Dear @daserk

Which version of SOFA did you install?
Best wishes,

Hugo

[Hugo]

Yes it is no worry!

[Hugo]

Hey @joshuaf and @beichun

First in the InteractiveCamera, you can not define both the lookAt and the orientation.
However, I am not sure why changing the values in the InteractiveCamera do not update its actual position.

@froy would you have a idea on this?

Best,

Hugo

[Hugo]

Hi @anoushs

It appears that you are compiling the master branch of SOFA, where developments are done. This is no stable branch (just FYI).

The compilation error comes from the change introduced in SOFA by PR #1686. As written in the error:

Update your code by replacing #include<sofa/defaulttype/Vec3Types.h> with #include<sofa/defaulttype/VecTypes.h>

Could you please correct the STLIB plugin and pull-request your changes back to the repo?

Best,

Hugo

[Hugo]

Moreover note, that the first official release of SofaPython3 with SOFA will be done in the upcoming release v20.12. Before, SofaPython3 was a alpha version.

[Hugo]

Dear @shivamkp29

The SofaQtQuick was developed by an engineer @bmarques but the projet is over now. There is unfortunately no one for now active on this project for now.

You can find a working version using the dedicated “sqq_binaries” branch for:
– SOFA repository “SofaDefrost”, branche sqq_binaries
– SoftRobots: SofaDefrost, branche sqq_binaries
– SofaPython3: sofa-framework, branche sqq_binaries
– SofaQtQuick: SofaDefrost, branche sqq_binaires

Best,

Hugo

[Hugo]

Hi @sukhraj,

SofaPython3 will be integrated in the upcoming SOFA release v20.12.
Stay tuned in the coming days!

Best,

Hugo

[Hugo]

Hi @twxu

Using python scripts is not really suited for high speed simulation (especially if you have interaction from the script while simulation is running).
I am not familiar with Multithreading in python, but the walemark’s post gives a good hint.

@jnbrunet have investigated such aspects since then?

Best

Hugo

[Hugo]

Hi @twxu

Strange that it crashes when viewing the normals. Your mesh must have partial information. Could you try to add a TopologyModifier (e.g. TetrahedronSetTopologyModifier if you use a tetrahedral topology) with your topology description?

If it does not work, could you share more with us? files/scene

Best

Hugo

[Hugo]

Hi @twxu,

Congrats @scheikl for the explanations! Thank you and @sescaida for the tremendous help, so much appreciated to have support on the forum!

@twxu, about the PrecomputedConstraintCorrection requires to precompute once at the first time step the inverse of A-1 in order to then efficiently process all computations required for the constraint resolution:
– Lagrange multipliers solving :
– bring back the lambda (Lagrange multipliers) in 3D space: before computing the corrective velocity

Therefore, the more degrees of freedom (nodes) you have the longer it takes to precompute/store. And it will even be quadratic regarding your nb of nodes.

Never forget to take the time to read through the page about Lagrange constraints, especially here the section about ConstraintCorrection.

I am sorry for your other problem, could you summarize it again?

I hope it helps.
Best,

Hugo

[Hugo]

Dear @mckysd5

You are attempting to link the two data. This is indeed done using the setParent function:
mydata1.setParent(&mydata2)

But you have to make sure that the data type (here the Coord, type of DOFs) are the same on both sides. Did you also checked that the value of position is also changing in the GeomagicDriver?

Keep us updated.

Hugo

[Hugo]

Hey @yupeng,

You can use either your own way of exporting in a file in C++ (since you started to implement things on your own).
Otherwise, take a look at the VTKExporter for instance which allows to export positions, or any other nodal/element information.

Best

Hugo

[Hugo]

Dear @ajay,

When a package (2) is searched by a package (1) (because 1 has a dependency on 2), CMake has actually several ways to find it:
– using the SOFA_ROOT variable
– using the CMAKE_PREFIX_PATH variable
– using the config.h.in

If the package (2) is found using one of the two first ways, the CMake variable NAME_DIR will be set to NOT_FOUND by CMake. CMake should rather inform that the package was found another way.

In four words: no worry, it works.

Best

Hugo

[Hugo]

Dear @olumide

Thanks for highlighting this, this option is broken for some time. I think actually no one is really using it, I will discuss it on Wednesday dev meeting (every Wed on 10 am CET online, open to all). I created an issue here, feel free to watch this issue.

Best,

Hugo

[Hugo]

Dear @ajay,

This should be no problem. You will be able to compile.
I will see exactly why these code do not define their DIR variable.

Best,

Hugo

[Hugo]

Dear @ajay

Have you activated the plugin STLIB in CMake configuration (i.e. setting to true the CMake variable PLUGIN_STLIB) ?

Best

Hugo

[Hugo]

Dear @twxu

I would guess that your mesh has some issue (maybe duplicated edge). Could you check this ?
Best,

Hugo

[Hugo]

sorry I moved the above post, posted in the wrong topic.

[Hugo]

Dear @olumide

Me again!
Forcefields define any internal or external force applied to a mechanical system (if we talk about continuum mechanics). More generally, it could be defined as the function defining the evolutions of your system.

One single body, several forces can be acting in the same time:
– external pressure (surface forces)
– external volumetric forces (e.g. gravity)
– internal forces (mechanical constitutive law)

You were therefore right about ForceField.
Best,

Hugo

[Hugo]

Dear @olumide

First of all, thanks a lot for all your input on the forum and sorry for the delay of my reply!

Your feedback and analysis are very valuable, and in no way it is a critism. We love such a constructive approach.
You understood well the forces and weaknesses of SOFA (versatile grey-box, altough laking of documentation).
Another interesting point: you captured the difference between the scene graph and the graph of data (invisible -for now- in SOFA). Congratulations for understanding all this!

We currently are in the process of improving several of these weaknesses. Starting by the code organization (CMake project with many dependy issues), we work on changing the core of SOFA from a monolyth to a real modular core. Data dependency, documentation, performances are other topics that are / will very soon be addressed.

We would much appreciate help on the large documentation task. I would be glad to discuss further directly with you. Would you be open to this?

Best wishes,

Hugo

[Hugo]

Dear @nhnhan

Shell elements were implemented some times ago in a private plugin. I will update it and make it open-source soon. It requires two things:
– time that I spent to update / fix the code
– time that I spent for the administrative validation for open-sourcing

As soon as it will be done, we will communicate about this on our social media (twitter) and on the SOFA marketplace. Stay tuned!

Best,

Hugo

[Hugo]

Hey @scheikl

As we discussed during our training session, the collision response proposes mainly two approaches:
– the penalty (or penality) approach
– the full constraint resolution using Lagrange multipliers

The contactStiffness defined in any CollisionModel will be used in case of penalty. This stiffness will corresponds to the stiffness of springs, dynamically added during the simulation when a collision occurs.

The ProximityIntersection will use the contact information (collision models, contact alarm and contact distance) to compute the DetectionOutput and this “value” corresponding to the interpenetration.

If I understand correctly you would like to keep the contact info even once the contact is solved ? correct ?

Best

Hugo

[Hugo]

Hey @peter

Have you installed python (2.7 here in your case) on you Windows ?
See the paragraph about Python here.

Best

Hugo

[Hugo]

Hi @anoushs

Welcome on the forum!
You are explaining that you have an error at the compilation time, right?
I assume you therefore have no error at the configure/generate (CMake) phase. Is it correct?

As @nhnhan said, we will need the full error description.
Could you share this with us?

Best

Hugo

[Hugo]

Thank you so much Olumide.
Keep us updated about your progress and your first steps in SOFA. We are looking forward to it. What are you aiming at doing with SOFA?

Meanwhile I will close this topic.
Do not hesitate to open an new one as soon as you face any issue.

Best wishes,

Hugo

[Author]

Posts