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Hi,
Here are the scene and data.
Thanks!Hi Hugo,
Here are the data and the scene file that I used.
Can u help me to have a test? The error makes me so confused.Thanks in advance.
Best,
LujainHi Hugo,
You are right. THis is what i want. But when I use the example you gave, it reminds me to set tetrahedirc topology in TetrahedronFEMForceField. But it seems the mesh has already been the volumetric one.
So I think it may be casued by the line <Mesh src=”@loader” />. After I changed the loader into meshLoader, it reminds me the following errors:
`[ERROR] [Mat] invertMatrix finds too small determinant, matrix = [0 0 0,0 0 0,0 0 0]
[ERROR] [Mat] invertMatrix finds too small determinant, matrix = [0 0 0,0 0 0,0 0 0]
[ERROR] [Mat] invertMatrix finds too small determinant, matrix = [0 0 0,0 0 0,0 0 0]
[ERROR] [Mat] invertMatrix finds too small determinant, matrix = [0 0 0,0 0 0,0 0 0]
[ERROR] [Mat] invertMatrix finds too small determinant, matrix = [0 0 0,0 0 0,0 0 0]I have no idea about how to deal with these kind errors, and you? Thanks very much!
Best,
LujainHi Hugo，
Sorry for late reply again!
For the first question, I extracted two surfaces from the volumetric mesh(before and after deformation) and did initial registration between them. Now I want to apply the effect of the registration into the volumetric mesh when it is deformed. But I have no idea how to achieve this. This is why I want to apply force filed on surface. I already build my own simulation and hope that i explained clearly.
Best,
LujainHi Hugo,
Sorry for very late reply.
I did registration with two data sets of two surface. But I can only get the displacement.
I means that in this case how I can apply force field without tetra meshes?Best!
Hi Hugo,
Yes you are right. The femur_f seems always be the target of the registration process.
My meshes are the surface extracted from the volumetric meshes. But I am confused at that femur_m_res fileAnyway, thanks,hugo
BEST,
LujainHi Hugo,
BTW, why can’t an elastic model with co-rotational approach?
In the PH.D thesis “Augmented Reality and Numerical Simulations for Hepatic Tumors Resection” written by Rosalie Plantefeve, She told me before taht she used a corotational tetraedral FEM force field to model the liver parenchyma. And used either some plane force fields that manually placed on the anterior and superior surfaces of the liver to apply the pressure. But i dont know how to achieve that. Can you give me some tips?Thank you, Hugo!
Hi Hugo,
Sorry for late reply.
Here are mesh and scene file
I was busy to understand the algorithms in FEMforcefield cuz the deformation is not the one that I need. The liver is under pneumoperitoneum. So I guess I should do something with the component or the algorithms. As I have asked for help in programming with SOFA forum.
Can you give me some advice about both constraint and forcefield?BR,
LujainHi Hugo,
Thanks a lot for your kind explanation.
That means the “deforme” is done as follows: when one tetrahedron is rotated, we computed the displacement of the four vertices first right?
But I was also confused about why there are operation of the three vertices based on the one vertices?
deforme[1][0] -= deforme[0][0];
deforme[2][0] -= deforme[0][0];
deforme[2][1] -= deforme[0][1];
deforme[3] -= deforme[0];
And the dispalcement for the first vertice is directly set to 0: D[0] = 0;D[1] = 0;D[2] = 0; So why?
Sorry to trouble you and thanks again!BR,
LujainHi Hugo,
Thanks very much. I am trying to understand the code and the paper helps a lot.
But I still dont understand why there are computation of D[0]…D[11] and the deforme.Hi,
Here are some confusing problem.
First,I can just get the IDs of the selected ponits that I need(using Paraview、both the antirior margin and the bottom surface). There are problems when i used these ids in FixedConstraint. The position of vertices(selected ids) in behavior model are not the posiotn in my mesh. It seems to be in the up surface not the botton surface. I dont know whether SOFA did
some optimization or not.So do you think what’s the problem?
Second,when I tried using the BoxROI,i can only select coordinate of two vertices randomly. The region i got is somehow not the exact region that i want. How can I select the proper points to make right region of the BOX?<BoxROI name=”fixed_indices” box=”109.472 178.252 -281.232 -22.1038 95.1642 -335.919″ drawBoxes=”0″/> <FixedConstraint name=”FixedConstraint” indices=”@fixed_indices.indices”Best,
LujainHi Hugo,Hi jnbrunet
I am trying to solve the problem using Paraview. I am not good at this software and trying to learning. Can you give me some information in detail about getting ids? And I will try to use BoxROI to read them.
Any further progress, I will reply later.
Thanks so much for your kind help!BR,
LujainHi jnbrunet,
Thank you so much for your reply and I am so sorry for not saying clearly.
Ok, there is a line “<FixedConstraint name=”FixedConstraint” indices=”3 39 64″ />” in the liver.scn example. If I changed “3 39 64” by another three number like “5 4 8”,I will get another three particles in runSofa. And i can also increase to more vertices,right? Now I want to extract the whole edge of the liver as the constraint, how can I know the number of these vertices expressed like “3 39 64”?Hi Hugo,
I choose the easier way: getting some .vtu files using VTKExporter and load them using MeshVtkLoader. I can use my mesh to do some deformable experiments now.
Thanks a lot.Lujain
Hi,
I modified the MeshGenerationFromImage.scn in the line:<VTKExporter name=”exporter” filename=”data/output.vtu” XMLformat=”1″ edges=”0″ tetras=”1″ listening=”true” exportAtBegin=”true” cellsDataFields=”generator.outputCellData” overwrite=”true”/>by changing the filename=”output”. Now it can export the vtu file and can be shown in Paraview.
Hi Hugo,
I opened another topic about the output problem about cgal4.7.We can close this topic.
Thanks very much.Hi Hugo,
Thanks very much. You helped me a lot and I can load my *.mesh file in SOFA now.
Then I will follow your advice to do next work.By the way, I also used CGALplugin to generate mesh using MeshGenerationFromImage.scn. But when I test the scene itself.It can generate mesh but can’t create vtu file. Ok,I will pull another topic.
Thanks again for your help.
Best Regrads.
Lujain
