[Insight-users] How to ask to get answer

[Jorge]

Hi Ali,

I have been doing some research on itkFEM package for deformation
purposes. You may follow these steps:

1) First of all you will need a tetrahedral cell-based mesh. There a re
some vtk examples in which you can look for. (e.g. use a vtkSphere and
then using vtkDelaunay3D filter generate a tetrahedral mesh)

1b) Take a look in InsightApplications/FEM Examples to get used to the
itk::Fem package. 

2) Import the vtkUnstructuredGrid data to the itk::fem data structure
using Element3DCOLinearTetrahedronStrain elements.

3) Then you may define the Boundary conditions by using itk::fem::LoadBC
in order to lock the desired cells.

4) Add external loads to the system, by using LoadNode Class.

5) Init the FEM solver. Use Linear/Hyperbolic depending on your needs.

6) Solve your system and extract the displacements of the mesh. Take a
look on InsightApplications/FEM/FEMTruss.cxx (last loop).

7) Finally update your original vtkUnstructured mesh with the resulting
points.

Remember this package has been developed for image registration
purposes, so you may not get real time performance, because of the
massive number of calculations required.

Hope it helps for you!

Jorge.

On Mon, 2009-08-31 at 14:48 +0100, Jorge wrote:
> Hi Ali,
> 
> I have been doing some research on itkFEM package for deformation
> purposes. You may follow these steps:
> 
> 1) First of all you will need a tetrahedral cell-based mesh. There a re
> some vtk examples in which you can look for. (e.g. use a vtkSphere and
> then using vtkDelaunay3D filter generate a tetrahedral mesh)
> 
> 1b) Take a look in InsightApplications/FEM Examples to get used to the
> itk::Fem package. 
> 
> 2) Import the vtkUnstructuredGrid data to the itk::fem data structure
> using Element3DCOLinearTetrahedronStrain elements.
> 
> 3) Then you may define the Boundary conditions by using itk::fem::LoadBC
> in order to lock the desired cells.
> 
> 4) Add external loads to the system, by using LoadNode Class.
> 
> 5) Init the FEM solver. Use Linear/Hyperbolic depending on your needs.
> 
> 6) Solve your system and extract the displacements of the mesh. Take a
> look on InsightApplications/FEM/FEMTruss.cxx (last loop).
> 
> 7) Finally update your original vtkUnstructured mesh with the resulting
> points.
> 
> Remember this package has been developed for image registration
> purposes, so you may not get real time performance, because of the
> massive number of calculations required.
> 
> Hope it helps for you!
> 
> Jorge.
> 
> On Sun, 2009-08-30 at 16:15 -0700, InfoSeekerr wrote:
> > Hi all,
> > 
> > I sent to ur forum thousands of time asking about a simple example regarding
> > how to apply FEM on vtkvolume, but no one helped me 
> > 
> > is there a problem in the question , I just need simple tutorial , simple
> > example
> > 
> > the tutorial on ITK site take about how to use FEM in regestration and that
> > not my project
> > 
> > wish I see any response please
> > 
> > best regards