[vtkusers] Fwd: Re:AW: vtkContourFilter not working onvtkStructuredGrid

Sebastian Gatzka sebastian.gatzka at stud.tu-darmstadt.de
Fri Mar 12 05:10:22 EST 2010


Hi again.

Attached you will find the code that should produce the iso surface, but 
displays nothing.
I even tried to apply the vtkAssignAttribute frinxor at gmail.com suggested ...
Nothing changes.

Hope you will find the mistake.
Have a nice day.
Sebastian

Am 10.03.2010 15:50, schrieb Rakesh Patil:
>
> Well, i dont think anything is wrong
>
> According to this,
>
> http://www.vtk.org/doc/nightly/html/classvtkContourFilter.html
>
> vtkContourFilter is a filter that takes as input any dataset and 
> generates on output isosurfaces and/or isolines. So that is not a 
> problem..
>
> Can u just get you final code what u have coded..??
>
> Thanks
>
> Regards
> Rakesh Patil
>
>
>     ---------- Original message ----------
>     From:Sebastian Gatzka< sebastian.gatzka at stud.tu-darmstadt.de >
>     Date: 10 Mar 10 17:43:19
>     Subject: [vtkusers] Fwd: Re:AW: vtkContourFilter not working
>     onvtkStructuredGrid
>     To: vtkusers at vtk.org
>
>     No, this doesn't work out.
>     I put Update()'s at every (possible) object but nothing happens.
>
>     Even chaning SetValue() and GenerateValues() doesn't change that.
>     So maybe there is something wrong with the data?!
>
>     I have a structured grid (called sGrid) and the scalar values are
>     defined at the cell centers:
>
>     sGrid->GetCellData()->SetScalars(T);
>
>     But I just pass the sGrid to the vtkContourFilter
>
>     vtkContourFilter *scalarIsoSurface vtkContourFilter::New();
>     scalarIsoSurface->SetInput(sGrid);
>
>     May this be the problem?
>
>
>     -------- Original-Nachricht --------
>     Betreff: 	Re:AW: [vtkusers] vtkContourFilter not working on
>     vtkStructuredGrid
>     Datum: 	Sat, 06 Mar 2010 09:34:59 +0530
>     Von: 	Rakesh Patil <rakeshthp at in.com>
>     Antwort an: 	Rakesh Patil <rakeshthp at in.com>
>     An: 	Sebastian Gatzka <sebastian.gatzka at stud.tu-darmstadt.de>
>
>
>
>     Hi Sebastian,
>
>     I see there is a small mistake over there in your code..
>
>     As far as my knowledge is concerned,
>
>     scalarIsoSurface->GenerateValues(0,0.1);
>
>     This statement should produce error. Coz, according to the
>     documentation given here
>
>     http://www.vtk.org/doc/release/5.4/html/a00323.html
>
>     GenerateValues takes two parameters if and only if second
>     parameter is a double array comprising of two elements min and max
>     range.
>
>     Even if this code executes without any error, then also no output
>     will be produced, because the first argument you are passing is 0.
>     First parameter tells the number of contours to be generated,
>     Second parameter tells within what range these contours should be
>     plotted.
>
>     What i guess is, either you change it that statement t o
>
>     scalarIsoSurface->SetValue(0, 0.1);
>
>     or
>
>     scalarIsoSurface->GenerateValues( n, sGrid->GetScalarRange() );
>
>     where n is number of lines you want, say 1, 5, 10, 12... whatever...
>
>     And then say update..
>
>     Am i correct David Sir..??
>
>     Thanks
>
>     Regards
>
>     Rakesh Patil
>
>
>         ---------- Original message ----------
>         From:"Sebastian Gatzka"< sebastian.gatzka at stud.tu-darmstadt.de >
>         Date: 05 Mar 10 22:50:50
>         Subject: AW: [vtkusers] vtkContourFilter not working on
>         vtkStructuredGrid
>         To: "'Rakesh Patil'"
>
>         Hm. The ->Update() did not work out.
>
>         What can be wrong? How can the data be not fed correctly?
>
>         *Von:* Rakesh Patil [mailto:rakeshthp at in.com]
>         *Gesendet:* Freitag, 5. M¤rz 2010 16:25
>         *An:* David Doria
>         *Cc:* Sebastian Gatzka; vtkusers at vtk.org
>         *Betreff:* Re: [vtkusers] vtkContourFilter not working on
>         vtkStructuredGrid
>
>
>         Ya, I had also done the same mistake... I had ommitted that
>         update statement.. By putting that update statement is should
>         definitley work.. (only if data is fed correctly)
>
>
>         ---------- Original message ----------
>         From:David Doria< daviddoria+vtk at gmail.com >
>         Date: 05 Mar 10 19:26:03
>         Subject: Re: [vtkusers] vtkContourFilter not working on
>         vtkStructuredGrid
>         To: Sebastian Gatzka
>
>         On Fri, Mar 5, 2010 at 8:41 AM, Sebastian Gatzka
>         <sebastian.gatzka at stud.tu-darmstadt.de
>         <mailto:sebastian.gatzka at stud.tu-darmstadt.de>> wrote:
>
>         Hello.
>
>         I really can't tell why my code is not gernerating the
>         iso-surface.
>         I have a structured grid (sGrid) filled with scalars.
>
>         I call the contour filter
>
>         vtkContourFilter *scalarIsoSurface vtkContourFilter::New();
>         scalarIsoSurface->SetInput(sGrid);
>         scalarIsoSurface->GenerateValues(0,0.1);
>
>         Compute the normal
>
>         vtkPolyDataNormals *sGridPolyDataNormal vtkPolyDataNormals::New();
>         sGridPolyDataNormal->SetInput(scalarIsoSurface->GetOutput());
>
>         Put them into a poly data mapper
>
>         vtkPolyDataMapper *scalarIsoSurfaceMapper
>         vtkPolyDataMapper::New();
>         scalarIsoSurfaceMapper->SetInput(sGridPolyDataNormal->GetOutput());
>
>         and into an actor
>
>         vtkActor *scalarIsoSurfaceActor = vtkActor::New();
>         scalarIsoSurfaceActor->SetMapper(scalarIsoSurfaceMapper);
>
>         which is passed on to the scene
>
>         ren1->AddActor(scalarIsoSurfaceActor);
>
>         and NOTHING happens.
>
>         Any ideas what I have missed, or whats wrong?
>
>         Sebastian
>
>         You probably have a call to Render() after the code you sent
>         us, which I believe updates the whole pipeline. Whenever I
>         have something that is totally empty, I go back and put an
>         Update() call on every object that is updatable.
>
>         scalarIsoSurface->GenerateValues(0,0.1);
>
>         scalarIsoSurface->Update();
>
>         before I dig too deep.
>
>         If that doesn't change anything, try to create a demo
>         involving some simple data (using a vtk*Source if you can, so
>         we can reproduce it without needing your dataset). Then send
>         us the smallest compilable code that demonstrates the problem.
>
>
>         Thanks,
>
>         David
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20100312/24ac60ca/attachment.htm>
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: isoSurface.cpp
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20100312/24ac60ca/attachment.txt>


More information about the vtkusers mailing list