[vtkusers] Fwd: Re:AW: vtkContourFilter notworkingonvtkStructuredGrid

Sebastian Gatzka sebastian.gatzka at stud.tu-darmstadt.de
Fri Mar 12 06:05:42 EST 2010


I have checked it maybe a hundrert times.
I have tried different ranges, different numbers of surfaces, 
GenerateValues(), SetValue() even different colors (in case it collides 
with the background color).

And yes maybe my data has some problem - but I have absolutley NO idea 
what kind of.
The scalar data is properly displayed on a cutting plane, but I can't 
create iso surfaces.

Am 12.03.2010 11:59, schrieb Rakesh Patil:
>
> Try once again... Check code properly.. It should work.. else your 
> data may be having some problem..
>
> Thanks
>
> Regards
> Rakesh Patil
>
>
>     ---------- Original message ----------
>     From:Sebastian Gatzka< sebastian.gatzka at stud.tu-darmstadt.de >
>     Date: 12 Mar 10 15:57:21
>     Subject: Re: [vtkusers] Fwd: Re:AW: vtkContourFilter
>     notworkingonvtkStructuredGrid
>     To: vtkusers
>
>     Yes. Of Course I tried that.
>     Nothing changes.
>
>     Am 12.03.2010 11:19, schrieb Rakesh Patil:
>>     Hi,
>>
>>     Have you tried implementing what i told you.???
>>
>>     scalarIsoSurface->GenerateValues( 10, sGrid->GetScalarRange() );
>>
>>     this will solve your problem... As i told u before, there is no
>>     other prob i could figure out other than this.. GenerateValues
>>     takes three parameters, i.e.
>>
>>     1. Number of contour lines,
>>     2. min. value(of range)
>>     3. max value(of range)
>>
>>     It also takes two parameters.. in this case 2nd parameter is
>>     double array consisting two elements..
>>
>>     Thanks
>>
>>     Regards
>>     Rakesh Patil
>>
>>
>>         ---------- Original message ----------
>>         From:Sebastian Gatzka< sebastian.gatzka at stud.tu-darmstadt.de >
>>         Date: 12 Mar 10 15:40:22
>>         Subject: Re: [vtkusers] Fwd: Re:AW: vtkContourFilter not
>>         workingonvtkStructuredGrid
>>         To: vtkusers
>>
>>         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
>>>
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