[vtkusers] how to extract different connective fields out of a isosurface?

[alexandre gouaillard]

nihao,

I think what you're looking for is vtkPolyDataConnectivityFilter.
Just take a look at the html doc for more detailled descritpion, but here is
a copy of the general description of class' behaviour. In your case,
extracting and coloring each regions could be worth a try...

[...]
vtkPolyDataConnectivityFilter is a filter that extracts cells that share
common points and/or satisfy a scalar threshold criterion. (Such a group of
cells is called a region.) The filter works in one of six ways: 1) extract
the largest connected region in the dataset; 2) extract specified region
numbers; 3) extract all regions sharing specified point ids; 4) extract all
regions sharing specified cell ids; 5) extract the region closest to the
specified point; or 6) extract all regions (used to color regions).

This filter is specialized for polygonal data. This means it runs a bit
faster and is easier to construct visualization networks that process
polygonal data.

The behavior of vtkPolyDataConnectivityFilter can be modified by turning on
the boolean ivar ScalarConnectivity. If this flag is on, the connectivity
algorithm is modified so that cells are considered connected only if 1) they
are geometrically connected (share a point) and 2) the scalar values of one
of the cell's points falls in the scalar range specified. This use of
ScalarConnectivity is particularly useful for selecting cells for later
processing.

[...]

alex

----- Original Message -----
From: "戴 硕" <dai_shuo at hotmail.com>
To: <vtkusers at public.kitware.com>
Sent: Friday, March 29, 2002 10:35 AM
Subject: [vtkusers] how to extract different connective fields out of a
isosurface?


> hi, everyone
>    I've got an isosurface of bones from 2D CT data by using
> vtkMarchingCubes.
> There are several bones in it. Now I want to operate on each bone
> separately.
> How can I extract them from the same isosurface? In other words, how can I
> extract the different connective fields? Are there any vtk classes can
help
>
> me?
>    Any suggestions are greatly appreciated.
>                                                       Daishuo
>
>
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