[vtkusers] Surface from points

[Gib Bogle]

On 17/12/2010 9:11 a.m., David Doria wrote:
> On Thu, Dec 16, 2010 at 3:07 PM, Gib Bogle <g.bogle at auckland.ac.nz
> <mailto:g.bogle at auckland.ac.nz>> wrote:
>
>     I'm looking at a dataset that is a collection of (x,y,z) points that lie on
>     a complex surface.  The way the points are generated ensures that they are
>     closely spaced.  I want to generate and render the 3D surface in VTK.  I'm
>     guessing that this is a commonly-encountered situation, and I'm hoping that
>     someone can give me a quick pointer to the best way to approach it.
>
>     The points are actually in the form of 540 z-slices, and in each slice there
>     is a set of polygons, i.e. a set of (x,y) sequences.  The (x,y) point
>     spacing is less than the (constant) z spacing.  (The slices were extracted
>     from microscopic images.)  There are about 1,000,000 points.
>
>     Thanks.
>
>
> Take a look at these examples:
>
> http://www.vtk.org/Wiki/VTK/Examples/Cxx#Surface_reconstruction
>
> Particularly the ones that use:
> <http://www.vtk.org/Wiki/VTK/Examples/Cxx#Surface_reconstruction>vtkSurfaceReconstructionFilter
> <http://www.vtk.org/doc/nightly/html/classvtkSurfaceReconstructionFilter.html>
>
> Let us know how it goes.
>
> David

Well my Corei7 machine laboured mightily, and managed to generate a surface from 
the 1034680 points - an impressive feat.  I have to say that it doesn't look as 
I expected, but it is very interesting.  :-)  Now I have to decide whether it's 
right, and if not whether I did something wrong.  All I have to go on at the 
moment is the appearance of the individual slices, with their polygon sets. 
Apart from the fact that the surface looks more complex than I anticipated, it 
also has a distinct staircase character that I wouldn't expect to see at this 
resolution.  Altogether things are quite jagged while I'd expect them to be 
smooth.  I wasn't witness to the creation of this geometry, so I can't really 
vouch for its quality.  I'll delve further ...

Gib