[Wong]

Hello @hugo

Can you give me a reply?

Wong

[Wong]

Hello @hugo

This is my example. I hope you can literately help me. The issue is described in ReadMe.txt so you should be make sure that you read it beforehand.

https://www.dropbox.com/s/epexah0rjj49zh0/problem.rar?dl=0

The version of Sofa is 19.06. You can use your own method to modify(refine) the tetrahedral mesh because if I provide it, it would not necessarily be suitable.

Thanks
Wong

[Wong]

Hello @hugo

Well, however this plugin is extraordinarily hard. I once raised this issue on the forum but the author of the plugin did not give an example about free contacts on some local area of a soft body. And this plugin is temporarily used for soft robots not for free contacts.

So if any relevant developers & authors do not have time to patiently explain how to use the plugin, I can never learn how to use it.

Wong

[Wong]

Hello @hugo

Thank you for your reply.
Well, I have already tried the MOR plugin, but it is hard for me to define the shake function to meet my deformation requirement. In other words, it is hard for me to utilize it.

And unfortunately, I am not a French and my country is far away from France so I am not be able to go to the Symposium.

Thanks,
Wong

[Wong]

Hi @epernod,

Is there any progress about this problem?

Hello @Hugo,

I think it is a problem that relative to the update about Handling linearised constraints since
v18.06.

Can you notify the relevant developers? @fjourdes

Thanks,
Wong

[Wong]

Hello

This topic can be ignored. I have solved the problem.

[Wong]

Hello @hugo,

Do you get any information about it?

Wong

[Wong]

Hello @epernod,

Have you solved the problem?

Wong

[Wong]

Hello @epernod,

Maybe you could not see the frame because I did a little modification about the Geomagic plugin.
I use just the v18.12.

Try this new one:
https://www.dropbox.com/s/t5zazy8mwek4jly/liver-18.12.scn?dl=0

Wong

[Wong]

Hello @hugo,

And what about suture? I want to know how it is going.

Wong

[Wong]

Hello @epernod,

I just modified the liver example and made a comparison.

In v17.12, there is no delay at all between the instrument state and the proxy omni state, while in v18.12, there is not little delay, even at 130 FPS, let alone 50 FPS.

You can see the difference in the video from this link:
https://www.dropbox.com/s/094a4pl7ffv40nq/liver.rar?dl=0

Wong

[Wong]

Hello @olivier-goury,

Thank you, I will give it a try.

Wong

[Wong]

Hello @olivier-goury,

I think it is not easy to design a satisfying shaking. Because the movement of the soft robots is usually regular, but the one of a deformable body being collided by an instrument is always uncertain. So it is really tricky to think how many actuators and where should I set and what the shaking method can be designed as. And it is a new application differ from the soft robot simulation, I am not sure if it can genuinely work.

And I have tested my scene using shakingSofia for about a day. I notice that if I want to expand the space of shaking, I should increase the rodRadius. But if I increase it to 8(I created two actuators), the FPS of the generated scene would go down to around 80. I do not think it is a great improvement of the performance, compared with the sparse fem scene.

Wong

[Wong]

Hello @epernod,

It is my scene.
I will show you a video about it later.

Wong

[Wong]

Hello @hugo,

Has the simulation of suture and knot tying been done now?
If done, and possible, I can pay for it to use the plugin. Otherwise, I can take part in the discussion and help develop.

Thanks
Wong

[Wong]

Hello @olivier-goury,

Thank you for your reply.

I use shakingSofia to shake my model. And I used your command to check the shaking and then I found that indeed I had made a wrong configuration of the shaking.

I also saw that if the shakingSofia is used, the actuator would be rotating about axis Z. But sometimes I want it to rotate about axis X. How can I do it?

Thanks
Wong

[Wong]

Hello @olivier-goury,

I have been testing the plugin for about a week. And now I want to report some issues.

1) The crash and slowness situation still exist in v18.12 on Windows. It is quite a headache, and I do not know why either.

2) I know the MOR plugin is mainly applied to soft robot simulation. So I think it is an active plugin to actuate the deformable body to move. But I want to use this plugin in a haptic feedback scene where the deformable body is passive, being collided by an instrument.
So I want to know if this plugin is genuinely feasible to be used in a haptic feedback scene.

3) Anyway, I still have a try using Geomagic in my brain scene created by myself. But it is very difficult to configure the fixed ROIs and the actuactors and the parameters to generate a reduced brain model.
My brain model has two parts: the upper part and the lower part. When I use the instrument to push one part, the other part would deform abnormally.
Here is the relevant files and the video link:
https://www.dropbox.com/s/4ohm7d36d2wnamu/b2.rar?dl=0
Can you tell me if my scene is configured correctly? If not, can you help me correct it?

Thanks
Wong

[Wong]

Hello @epernod,

I have said that if this data binding is canceled, it will cause a large delay between the instrument state and the proxy state in a low FPS(say, 50Hz) scene.

And the old scenes do not work anymore in v18.12, even the one using RestShapeSpringsForceField. I have had all the tests.

Wong

[Wong]

Hello @epernod,

You can see the change as the pictures shown below.

In v17.12, there is a data binding.

While in v18.12, the data binding is removed.

Wong

[Wong]

Hello @damien-marchaluniv-lille1-fr,

I tried to use this plugin, but it is very likely to cause a crash. And the prerequisite that you use SofaDistanceGrid as a collision model of a deformable object is that you use the HexahedronFEMForceField, but sometimes I want to use the TetrahedronFEMForceField.

I give you the scene, you can have a test.

<?xml version="1.0"?>
<Node name="root" dt="0.02">
    <VisualStyle displayFlags="showBehaviorModels showForceFields" />
    <RequiredPlugin name="SofaDistanceGrid" pluginName="SofaDistanceGrid"/>
    <RequiredPlugin name="SofaSparseSolver" pluginName="SofaSparseSolver"/>
    <CollisionPipeline />
    <BruteForceDetection />
    <FreeMotionAnimationLoop/>
    <GenericConstraintSolver maxIterations="1000" tolerance="0.001"/>
    <DefaultContactManager response="FrictionContact" responseParams="mu=0.6"/>
    <MinProximityIntersection alarmDistance="0.8" contactDistance="0.5"/>
    <Node name="cubeFEM">
        <EulerImplicit name="cg_odesolver" printLog="false"  rayleighStiffness="0.1" rayleighMass="0.1" />
        <SparseLDLSolver name="SolverCube1" />
        <MechanicalObject />
        <UniformMass vertexMass="0.25" />
        <RegularGrid nx="5" ny="5" nz="5" xmin="-3.5" xmax="3.5" ymin="-3.5" ymax="3.5" zmin="-3.5" zmax="3.5" />
        <TetrahedronFEMForceField name="FEM" youngModulus="25" poissonRatio="0.3" computeGlobalMatrix="false" updateStiffnessMatrix="false" method="large" />
	<LinearSolverConstraintCorrection solverName="SolverCube1"/>
        <Node name="Visu">
            <OglModel name="Visual" fileMesh="mesh/smCube125.obj" color="red" />
            <SubsetMapping input="@.." output="@Visual" />
        </Node>
        <Node name="Surf">
            <MeshObjLoader name="loader" filename="mesh/smCube125.obj" />
            <Mesh src="@loader" />
            <MechanicalObject src="@loader" />
            <Triangle />
            <Line />
            <Point />
            <SubsetMapping />
        </Node>
    </Node>
    <Node name="Floor" activated="1">
        <OglModel name="FloorV" fileMesh="mesh/floor3.obj" texturename="textures/brushed_metal.bmp" dy="-10" scale="1.75" />
	<DistanceGrid fileRigidDistanceGrid="mesh/floor3.obj" scale="1.0" usePoints="0" proximity="0.5" contactStiffness="5.0" contactFriction="0.0" />
    </Node>
</Node>

Wong

[Wong]

Hello @felixvanneste,

I am really grateful that you notice me again and tell me what you are working on because I was once afraid that you won’t give me a reply anymore. (o_o)

It does not matter that you have no clue about the issue because at least it still can work after I try a few more times.

Now I will use MOR plugin in my own scene to test if it works. If I have problem, I will inform you on this topic and wait for your reply until you have time to respond.

Thanks
Wong

[Wong]

Hello @olivier-goury,

Have you corrected the plugin yet?

Wong

[Wong]

Hello @damien-marchaluniv-lille1-fr,

Have you thought of it yet?

Wong

[Wong]

Hello @damien-marchaluniv-lille1-fr,

Yes, I think that is just the kind of the component I am looking for.
Hope you to remember.

Wong

[Wong]

Hi @hugo,

As far as I know, RepulsiveSpringForceField is a particle-to-particle component, not particles-to-particles component. So I do not think it would work.

Can you give me an expamle?

Wong

[Author]

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