[vtkusers] help with finding a surface

[Jérôme]

Hi,
Don't worry about the grey and blue : what I meant is that I understood that
you have a volume (vtkImageData) that contains some scalars (tell me if I am
wrong). The way it is rendered (grey, blue, or what you want) is not
important.

In your case, the surface does not lie on a constant value and this is why,
effectively, marching cube is not the direct solution. An idea would be to
use vtkThreshold (not vtkImageThreshold!) in order to keep the points that
have a value higher than a chosen one (your maxima). Then try a delaunay
triangulation, in order to reconstruct the surface. If delaunay is not
efficient enough, you may find some surface reconstruction filters on the
Midas VTK journal.

If you can share your data, maybe I could take a look.

Best regards,
Jerome

2011/6/13 nuno.jf <nunofernandes7 at gmail.com>

> Hi,
>
> I apologize if I'm being lay but I think vtkImageMarchingCubes doens't do
> what I need.
> Let me put the things this way:
> - I have N point clouds corresponding to a surface, that are aligned using
> ICP and the aligned points are placed in an 3D image;
> - I have a great dispersion of the surface points, probably due to my
> scanner quality (resulting from artifacts or low accuracy...);
> - The only thing I know is the maximum number of points I get in one voxel
> in the image.
>
> What I really need is an algorithm that finds the regions in the surface
> where I have the biggest density of points and generates the isosurfaces
> passing trough those regions. vtkImageMarchingCubes requires the user to
> set
> the contour value or a range of values. I can give it some values, but what
> I really want is to find the regions where there is a biggest density,
> because the density can have local maximum/minimum values. If I set the
> values, I will automatically limit the contouring.
> Once again, thank you very much for your help (and patience because I can
> be
> a little boring xD)
> BR,
> Nuno
>
> PS: I don't know if this is relevant or not, not even if this is
> innapropriate, but I don't have specific values like grey or blue. Sorry
> for
> any incoherence, but some terms are new to me.
>
> --
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