[Insight-users] DeformableMesh3DFilter with an open mesh

[Luis Ibanez]

Hi Georgi,

This is an unfortunate but normal behavior.

It is somehow due to the fact that the surface is open,
but it could occur also with closed surfaces.

In practice it means that you should massage more the
vector field that drives the evolution of the surface.

One option is to play with the stiffness of the surface,
Another option is to scale the values of the vector field.


You may want to look at the application:

    InsightApplications/
        DeformableModelSimplexMesh/


That give you a visualization of the mesh as it is deforming.
Such visual feedback is very useful for identifying the
parameters that may need to be fine tunned.



Regards,


     Luis


---------------------
Georgi Diakov wrote:
> Dear All,
> 
> I have aplied the DeformableMesh3DFilter to segment bone from CT images.
> The initial mesh is a result from thresholding and marching cubes
> triangulation. It is an open surface, e.g. only a patch, delineating a
> region on the bone. If the number of iterations is set high enough
> value, in order to reach convergence, the whole mesh gets shifted into
> the corner of the image. 
> 1. Does anybody know, if the reason for that shift could be, that the
> mesh is not a complete closed surface?
> 2. Is there a way to limit the range of influence of the gradient
> forces, so that they affect only nodes, which are in close neighbourhood
> of the contour? Could this be done with reducing the GradientMagnitude?
> Actually, reducing the GradientMagnitude only diminishes the
> deformation; I haven't established an influence on the range of effect
> of the forces.
> 
> Thanks for the help!
> Georgi
> 
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