[vtkusers] How to create 3d surface from vtkPolyData?

[Lars Friedrich Lars]

Andrej,

it's possibly right that all input points are double-casted integers. However, the example nicely shows how to overcome the primary limitation of vtkVoxelContoursToSurfaceFilter by adapting the underlying voxel-spacing and converting to ijk-coordinates first, and then back-transforming the output mesh to world coordinates again.

Have a closer look on the code blocks statring with these comments:

// Convert to ijk coordinates for the contour to surface filter

and 

// Rescale the output back into world coordinates and center it

.

HTH,
lars

-------- Original-Nachricht --------
> Datum: Fri, 4 Feb 2011 16:50:42 +0300
> Von: Andrej Gluhov <realandron at gmail.com>
> An: David Doria <daviddoria at gmail.com>, vtkusers <vtkusers at vtk.org>
> Betreff: Re: [vtkusers] How to create 3d surface from vtkPolyData?

> Yes, I looked. In this example all points are integer values in double
> format. My contours have points with double value...
> 
> vtkVoxelContoursToSurface description:
> 
> create surface from contours
> 
> vtkVoxelContoursToSurfaceFilter<http://www.vtk.org/doc/nightly/html/classvtkVoxelContoursToSurfaceFilter.html>is
> a filter that takes contours and produces surfaces. There are some
> restrictions for the contours:
> 
>    - The contours are input as
> vtkPolyData<http://www.vtk.org/doc/nightly/html/classvtkPolyData.html>,
>    with the contours being polys in the
> vtkPolyData<http://www.vtk.org/doc/nightly/html/classvtkPolyData.html>
>    .
>    - The contours lie on XY planes - each contour has a constant Z
>    - The contours are ordered in the polys of the
> vtkPolyData<http://www.vtk.org/doc/nightly/html/classvtkPolyData.html>such
> that all contours on the first (lowest) XY plane are first, then
>    continuing in order of increasing Z value.
>    - *The X, Y and Z coordinates are all integer values.*
>    - The desired sampling of the contour data is 1x1x1 - Aspect can be
> used
>    to control the aspect ratio in the output polygonal dataset.
> 
> 
> 
> 2011/2/4 David Doria <daviddoria at gmail.com>
> 
> > 2011/2/4 Andrej Gluhov <realandron at gmail.com>:
> > > Hello.
> > >
> > > I have series of contours in vtkAppendPolyData. How to create surface?
> > > vtkVoxelContoursToSurface needs integer points!
> >
> > What do you mean it needs integer points? Have you looked at this
> > example
> > http://www.vtk.org/Wiki/VTK/Examples/Cxx/PolyData/ContoursToSurface
> > ?
> >
> > David
> >
> 
> 
> 
> -- 
> С Уважением,
> Андрей.
> Best regards, Andrew

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