[vtkusers] Image To PolyData

[David.Pont at ForestResearch.co.nz]

Hi Florian,
  just last week I found this from a search on the web:

http://www.crd.ge.com/~lorensen/seg12/

This is a good description of the 'iso-contour' approach, but you say you
dont want that...

To extract whole cells you could look at:
  vtkKWExtractGeometryByScalar
  vtkExtractGeometry where the implicit function uses the scalars (your 0
or 1)

'merging' a bunch of cubes into a 'single' polygonal object' sounds tricky.
If you are happy with a bundle of cubes (has many internal surfaces) that
is OK.
Otherwise you could try   vtkGeometryFilter  which should extract just the
outer surface.
If you really want a 'blocky' cube-based surface and not a contoured one
(from MarchingCubes etc) the ExtractGeometry filters should be a good
start.

  regards
      Dave




|---------+---------------------------->
|         |           Florian Schmidt  |
|         |           <mista.tapas at gmx.|
|         |           net>             |
|         |           Sent by:         |
|         |           vtkusers-admin at vt|
|         |           k.org            |
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|         |                            |
|         |           22/09/2003 09:03 |
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  |       To:       vtkusers at vtk.org                                                                                               |
  |       cc:                                                                                                                      |
  |       Subject:  Re: [vtkusers] Image To PolyData                                                                               |
  >--------------------------------------------------------------------------------------------------------------------------------|




On Sun, 21 Sep 2003 12:10:02 -0400
Glen Lehmann <glehmann at imaging.robarts.ca> wrote:

> Hi Florian,
>
> Have a look at vtkImageMarchingCubes or vtkImageSeedConnectivity then
> follow one of them up with vtkCleanPolyData.  That should be a good
> start.
>

Hi,

thanks for the tips, though an isocontour is not what i want. Let me try
to explain a little more [hard without being able to draw]. Let's say,
my Volume consists of all 0's except for one voxel which has scalar
value 1. As output i would like to get a polygone which is a cube [since
the voxel represents a volume in space not just a point].

Now, if i have multiple voxels in this volume with scalar value != 0, i
want a polygonal cube for each of them. And then i want those polygonal
cubes which are neighbours to be merged into a single polygonal object.

Maybe i misunderstood you though [and the manpages of the mentioned
filters]..

Regards, Florian Schmidt
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