[vtkusers] Using vtkContourFilter for Rendering a Point Cloud

[Cory Quammen]

Moritz,

You should be able to call GetPointData() on your unstructured grid,
which returns an object of type vtkPointData. This object has a
SetScalars() method which should allow you to associate your energies
with your points. It takes a vtkDataArray, of which vtkFloatArray is a
subclass.

Hope that helps,
Cory

On Sun, May 4, 2008 at 12:10 PM, Moritz Bernard Fricke
<Moritz.Bernard.Fricke at rwth-aachen.de> wrote:
> Cory,
>  i have still problems concernig the scalar warping in vtkGaussianSplatter. I can't use the ParticleReader because the files i'm using contain more information in a line. But the extraction from the file is already working, i have writting a parser doing that.
>
>  But if scalar warping is on, where does the filter get the scalars from? I have a list of floats that contains the energies of the particle? How can i use thme as scalars for the splats?
>
>
>  Moritz
>
>  ----- Ursprüngliche Nachricht -----
>  Von: Cory Quammen <cquammen at cs.unc.edu>
>  Datum: Mittwoch, April 30, 2008 9:34 pm
>  Betreff: Re: [vtkusers] Using vtkContourFilter for Rendering a Point Cloud
>  An: Moritz Bernard Fricke <Moritz.Bernard.Fricke at rwth-aachen.de>, vtkusers at vtk.org
>
>
>
>  > I'm copying to the vtkusers list as a reference so that in the future
>  > others with the same question as you.
>  >
>  > Take a look at vtkParticleReader. It looks like it does exactly what
>  > you want. It reads xyz coordinates and a scalar value.
>  >
>  > Cory
>  >
>  > On Wed, Apr 30, 2008 at 11:30 AM, Moritz Bernard Fricke
>  > <Moritz.Bernard.Fricke at rwth-aachen.de> wrote:
>  > > Cory,
>  > >  how can associate these scalar values in vtk? I think that is my
>  > major problem.
>  > >  So, I get the data for each point from a log-file from a ray
>  > tracing simulation for acoustics. Can I use vtkFloatArray to create
>  > an array of energies? And how can I associate these energies to the
>  > Points in my UnstructuredGrid?
>  > >  Thank you for your help, i'm running out of time with this project!
>  > >
>  > >  Moritz
>  > >
>  > >  ----- Ursprüngliche Nachricht -----
>  > >  Von: Cory Quammen <cquammen at cs.unc.edu>
>  > >  Datum: Mittwoch, April 30, 2008 4:59 pm
>  > >  Betreff: Re: Using vtkContourFilter for Rendering a Point Cloud
>  > >  An: moritz.bernard.fricke at rwth-aachen.de, vtkusers at vtk.org
>  > >
>  > >
>  > >
>  > >  > Moritz,
>  > >  >
>  > >  > If your unstructured grid has associated scalar data (in your
>  > case,>  > the energy of the points), then according to the
>  > documentation>  >
>  > (http://www.vtk.org/doc/nightly/html/classvtkGaussianSplatter.html),>  > you can tell the vtkGaussianSplatter to scale the values of the
>  > >  > splatted Gaussian by the scalar value using ScalarWarpingOn().
>  > >  >
>  > >  > Cory
>  > >  >
>  > >  > On Wed, Apr 30, 2008 at 10:04 AM,  <moritz.bernard.fricke at rwth-
>  > >  > aachen.de> wrote:
>  > >  > > Hi Cory,
>  > >  > >  thank you for your answer. i've tried it! I have just build an
>  > >  > Structured Grid of my Points and applied vtkGaussianSplatter
>  > at it.
>  > >  > That works, but i want to interpolate the values of the
>  > points. How
>  > >  > can I link the energy of one point to its position to make the
>  > >  > energy the criteria for the GaussianSplatter?
>  > >  > >
>  > >  > >  Thank you for your help,
>  > >  > >
>  > >  > >  moritz
>  > >  > >
>  > >  >
>  > >  >
>  > >  >
>  > >  > --
>  > >  > Cory Quammen
>  > >  > Department of Computer Science
>  > >  > University of North Carolina at Chapel Hill
>  > >  > http://www.cs.unc.edu/~cquammen
>  > >  >
>  > >
>  >
>  >
>  >
>  > --
>  > Cory Quammen
>  > Department of Computer Science
>  > University of North Carolina at Chapel Hill
>  > http://www.cs.unc.edu/~cquammen
>
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>



-- 
Cory Quammen
Department of Computer Science
University of North Carolina at Chapel Hill
http://www.cs.unc.edu/~cquammen