[vtkusers] Color a vtkcell

Wed Jan 13 09:08:09 EST 2010

On Wed, Jan 13, 2010 at 8:59 AM, awabi <aw.ndaw at gmail.com> wrote:
>
> Thank you François.
>
> With the code given before, the faces of my cube are colored with the same
> color. Iµ wants to color faces with differents colors.
>
> Thank you,
>
> Awa.
>
> Francois Bertel wrote:
>>
>> Just include vtkCellData.h:
>>
>> http://www.vtk.org/Wiki/VTK_FAQ#The_C.2B.2B_compiler_cannot_convert_some_pointer_type_to_another_pointer_type_in_my_little_program
>>
>> On Tue, Jan 12, 2010 at 7:21 PM, awabi <aw.ndaw at gmail.com> wrote:
>>>
>>> I try to use your solution but,
>>> 4) PolyData->GetCellData()->SetScalars(colors)  is not accepted I have
>>> this
>>> error:
>>>
>>>  error: invalid use of incomplete type ‘struct vtkCellData’
>>> /usr/sbin/../include/vtk-5.0/vtkDataSet.h:43: error: forward declaration
>>> of
>>> ‘struct vtkCellData’
>>>
>>> However when I replace the dtkCellData with a vtkPointData i haven't any
>>> error.
>>>
>>> Thanks,
>>>
>>> Awa,
>>>
>>>
>>> David Gobbi-3 wrote:
>>>>
>>>> No, the CellArray is for something else.  The best way is with RGB
>>>> scalars:
>>>>
>>>> vtkUnsignedCharArray *faceColors = vtkUnsignedCharArray::New();
>>>> faceColors->SetNumberOfComponents(3);
>>>> faceColors->InsertNextTuple(r1, b1, g1);
>>>> faceColors->InsertNextTuple(r2, b2, g2);
>>>>
>>>> Etcetera, until you have six colors.  Use values between 0 and 255 for
>>>> r,
>>>> g, b.
>>>>
>>>> Next is the tricky part.  I don't think that VTK has a pipeline filter
>>>> that allows you to add these scalars (except for the programmable
>>>> filters) so the easiest way to add the colors is like this:
>>>>
>>>> 1) make a vtkCubeSource
>>>> 2) make a vtkPolyData
>>>> 3) DeepCopy the output of the CubeSource into the PolyData
>>>> 4) do PolyData->GetCellData()->SetScalars(colors) as Darshan said
>>>>
>>>> Does anyone know if there is a VTK filter that can add field data or
>>>> attribute data to a dataset, so that these sorts of DeepCopy tricks
>>>> aren't necessary?
>>>>
>>>>    David
>>>>
>>>>
>>>> On Tue, Jan 12, 2010 at 3:27 PM, awabi <aw.ndaw at gmail.com> wrote:
>>>>>
>>>>> Thank you.
>>>>>
>>>>> Is it possible via a vtkcellarray?
>>>>>
>>>>> awa.
>>>>>
>>>>> dpai wrote:
>>>>>>
>>>>>> Yes you can
>>>>>>
>>>>>> Add Attributes as follows PolyData->GetCellData()->SetScalars()
>>>>>> and put a lookupTable with the required colors
>>>>>>
>>>>>> On Tue, Jan 12, 2010 at 5:03 PM, awabi <aw.ndaw at gmail.com> wrote:
>>>>>>
>>>>>>>
>>>>>>> Hello,
>>>>>>>
>>>>>>> I'd like to know if it is possible with vtk to color the faces of a
>>>>>>> vtkpolydata as I want. For example I have a cube and I'd like to
>>>>>>> color
>>>>>>> the
>>>>>>> faces differently.
>>>>>>>
>>>>>>> Thank you,
>>>>>>>
>>>>>>> Awa
>>>>>>> --
>>>>>>> View this message in context:
>>>>>>> http://old.nabble.com/Color-a-vtkcell-tp27135594p27135594.html
>>>>>>> Sent from the VTK - Users mailing list archive at Nabble.com.
>>>>>>>
>>>>>>> _______________________________________________
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>>>>>>
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>>>>>>
>>>>>> Visit other Kitware open-source projects at
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>>>>>>
>>>>>
>>>>> --
>>>>> View this message in context:
>>>>> http://old.nabble.com/Color-a-vtkcell-tp27135594p27135949.html
>>>>> Sent from the VTK - Users mailing list archive at Nabble.com.
>>>>>
>>>>> _______________________________________________
>>>>> Powered by www.kitware.com
>>>>>
>>>>> Visit other Kitware open-source projects at
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>>>>>
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>>>>
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>>>
>>> --
>>> View this message in context:
>>> http://old.nabble.com/Color-a-vtkcell-tp27135594p27137548.html
>>> Sent from the VTK - Users mailing list archive at Nabble.com.
>>>
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>>>
>>> Visit other Kitware open-source projects at
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>>
>>
>>
>> --
>> François Bertel, PhD  | Kitware Inc. Suite 204
>> 1 (518) 371 3971 x113 | 28 Corporate Drive
>>                       | Clifton Park NY 12065, USA
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
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>>
>
> --
> View this message in context: http://old.nabble.com/Color-a-vtkcell-tp27135594p27145338.html
> Sent from the VTK - Users mailing list archive at Nabble.com.
>
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>
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What did these 6 lines look like: ?

faceColors->InsertNextTuple(r1, b1, g1);
faceColors->InsertNextTuple(r2, b2, g2);
...

Can you post the shortest piece of code which compiles and
demonstrates your problem?

Thanks,

David