SOFA jjcasmar

jjcasmar replied to the topic Preconditioner for an iterative solver in the forum Using SOFA 3 weeks, 2 days ago

Well, that depends on your preconditioner. For my particular use case, the preconditioned can be represented as a matrix, but its easier to represent it as some functions, kind of matrix-free preconditioner. I think saying that a its based on a external linear direct solver may arise to some misconceptions later. Better to just say that is has to…[Read more]
jjcasmar replied to the topic Preconditioner for an iterative solver in the forum Using SOFA 3 weeks, 2 days ago

Thanks Hugo. I have read the document you proposed and I think that this: The ShewchukPCGLinearSolver allows to choose the preconditioner of our choice based on an external direct linear solver: LULinearSolver, SparseLDLSolver, etc Is not exactly correct.

From reading the source code, I think any linear solver can be used, not only direct linear…[Read more]
jjcasmar replied to the topic Preconditioner for an iterative solver in the forum Using SOFA 3 weeks, 6 days ago

So ShewchukPCGSolver is a preconditioned conjugate gradient implementation. Why is not the default CG implementation? Seems like it is a bit hidden…

If I understand correctly, I just need to provide an implementation of my preconditioner, deriving it from sofa::core::behavior::LinearSolver and link it to the preconditioners property, right?
jjcasmar started the topic Preconditioner for an iterative solver in the forum Using SOFA 1 month ago

I have been looking for preconditioners in SOFA but I havent been able to found any way to use them. Is there anyway to use a preconditioner or implement our own to use with the CG solver?
jjcasmar started the topic Implement a velocity constraint in the forum Programming with SOFA 1 month, 1 week ago

Hi,

I am trying to implement an AngularVelocityConstraint. I am looking at the LinearVelocityConstraint for inspiration and I see that if the constraint is still active (if(finished)...), it applies some corrections to the positions, but if not, it doesn’t. Is this the correct behavior? Do I need to apply the constraint to both the velocity and…[Read more]
jjcasmar replied to the topic Basic collision scene not working properly in the forum Using SOFA 3 months, 1 week ago

Okay, was my problem. Didnt realize the the example scene I was looking to had the fixed collider outside the scope of the ODESolver and the CGSolver. I have put my shere outside the scope of my ODESolver and now is fixed.
jjcasmar replied to the topic Mass below a multimap in the forum Programming with SOFA 3 months, 1 week ago

I have compiled in debug mode to check what is happening and I confirm that masses are mapped through the mapping, at least when using a matrix-free solver like CG
jjcasmar started the topic Basic collision scene not working properly in the forum Using SOFA 3 months, 1 week ago

I am trying to make a basic scene with collisions, made of one plane under gravity and a not simulated sphere. Both objects have collision models and I am expecting to see the plane collide against the sphere. What I am seeing is the sphere breaking and deforming in a very strange manner. I have posted the scene in my nextcloud, as apparently…[Read more]
jjcasmar started the topic Mass below a multimap in the forum Programming with SOFA 3 months, 1 week ago

I have a scene in which I have two sets of independent dofs (x and d) and one set of mapped dofs (p). The mapping is a multimap with the following expresion: p = Bx + d
I also have a projective constraint on d.
I have tested all of my components and everything seems to be working fine, but when I simulate a basic triangular mesh under gravity with…[Read more]
jjcasmar replied to the topic Initialize degrees of freedom in the forum Programming with SOFA 3 months, 2 weeks ago

Okay, I see the point. If the DataEngine initializing the data is after the MO, the MO init function will be called before the init function of my DataEngine so the MO will see nothing when executhing the link, no?
jjcasmar replied to the topic Initialize degrees of freedom in the forum Programming with SOFA 3 months, 2 weeks ago

Not sure I can share my scene. It uses some plugin code I can’t share atm.
I am trying to initialize my degrees of freedom using a DataEngine. Still, its a bit unclear what is the order of initialization of the different components in a scene. Any hint about this?
jjcasmar replied to the topic Debug a plugin in the forum Programming with SOFA 3 months, 2 weeks ago

Apparently the plugin was compiled without debug symbols, not sure why. I have wiped the plugin build directory and rerun cmake and now the compiler is adding the correct flag for building the debug symbols.

With that, in case anyone need it in the future: I am using linux and qtcreator as IDE. I just need to ‘Start and Debug an external…[Read more]
jjcasmar started the topic Initialize degrees of freedom in the forum Programming with SOFA 3 months, 2 weeks ago

I have a scene with 3 mechanical objects. 2 mechanical objects contain independent DoFs and the third one contain mapped values. The issue is that at startup, the values I know are the mapped values, as they directly from a mesh, but it looks like at startup the values are propagated from independent dofs to mapped dofs (which makes sense).

I am…[Read more]
jjcasmar replied to the topic Available objects in the factory (python or xml) in the forum Programming with SOFA 3 months, 2 weeks ago

Wow, awesome work! Ill check ASAP!
jjcasmar started the topic Debug a plugin in the forum Programming with SOFA 3 months, 2 weeks ago

I am developing a plugin and I want to do some debugging but I am not sure how to do it. I am using the SofaPython3 plugin and using a python scene.
Sofa and SofaPython3 are compiled in Release mode, and my own plugin is compiled in Debug mode.

I have tried to start runSofa with my python scene and attach a debugger to the process, but haven’t…[Read more]
jjcasmar started the topic Available objects in the factory (python or xml) in the forum Programming with SOFA 4 months ago

I am trying to create some SOFA scenes , but I’m having some trouble trying to know the name of the objects or the properties it has.

In python for example I have:

def createScene(node): node.addObject("GridMeshCreator", resolution=[2,2])

I copied this from a .scn file
<GridMeshCreator name="loader" filename="nofile" resolution="2 2"…[Read more]
jjcasmar replied to the topic Linking issues with plugin when loading it in the forum Programming with SOFA 4 months, 1 week ago

Hi @Hugo, you can find all the code in the gitlab (its easier to share it that way). Anyway, @jnbrunet solution works fine.
Shouldnt the .inl be already included in sofa/core/MultiMapping.h?
jjcasmar started the topic Linking issues with plugin when loading it in the forum Programming with SOFA 4 months, 1 week ago

I am trying to implement a plugin with some new mappings. For now, I am just trying a test case, implement something equivalent to the IdentityMultiMapping.

My code compiles fine, but when I try to load the plugin in a scene, I get a linking issue:

`
[ERROR] [PluginManager] Plugin loading failed…[Read more]
jjcasmar replied to the topic Is SOFA tailored for the linear system in the forum Using SOFA 7 months, 3 weeks ago

Would it make sense to provide some default integration schemes in which you can specify the number of Newton steps done per time step?
jjcasmar started the topic Mapping 2 states to one state in the forum Programming with SOFA 7 months, 3 weeks ago

Hi there!

I would like to know how to create a mapping of several states to one single state. I have some forces that depend on a state, but that state is defined kinematically as the sum of two other states (which are my degrees of freedom).
p = Bv + x

I have checked core::mapping and BaseMapping and in both cases they talk only about mapping…[Read more]
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jjcasmar

@jjcasmar