[Ves] How to color polydata with Scalars in VES

[Bo Yu]

Thank you for your suggestion, Casey.
If I understand correctly, now I am try to use "vesKiwiViewerApp", and I
didn't call any shader init function in it,  so I think I am using the
default shader.
Now I can color the model via vertexes using default shader with helps from
you and Aashish.
However, if I want to specify colors for some cells of the model, do I have
to call the functions related with the shaders in vesKiwiViewerApp?
Sorry but I know little about this, is there some documents about how to
achieve this goal?
Thank you very much.

Best regards,
Bo Yu



On Thu, Feb 27, 2014 at 12:01 AM, Casey Goodlett <casey.goodlett at kitware.com
> wrote:

> Bo,
>
> Are you using the default shader?  I think you should specify colors
> per-vertex rather than per-cell with the default shader.
>
>
> On Tue, Feb 25, 2014 at 10:26 AM, Bo Yu <yubo1983 at gmail.com> wrote:
>
>> Thank you, Aashish, I tried to set name of a vtkDataArray, but that
>> didn't make change,I still only see model with no color (or white color).
>> if you have time could you please check my code below?
>> I just create a simple triangle and try to paint it to red use
>> colorByScale.
>> However, It seems I can not change the color mode of "rep" in the last
>> three lines. It always have the value as "Solid color"....
>> Sorry, I just start to learn ves, and thank you so much for your reply
>> and patient.
>>
>> Sincerely yours,
>>
>> Bo Yu
>> /////////////////////
>> /////testing
>>     // Setup points
>>     vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
>>     vtkSmartPointer<vtkCellArray> vertices =
>> vtkSmartPointer<vtkCellArray>::New();
>>     points->InsertNextPoint(0.0, 0.0, 0.0);
>>     points->InsertNextPoint(1.0, 0.0, 0.0);
>>     points->InsertNextPoint(0.0, 1.0, 0.0);
>>
>>     // Setup colors
>>     unsigned char red[3] = {1, 0, 0};
>>     vtkSmartPointer<vtkUnsignedCharArray> colors =
>> vtkSmartPointer<vtkUnsignedCharArray>::New();
>>     colors->SetNumberOfComponents(3);
>>     colors->SetName("Colors");
>>     colors->InsertNextTupleValue(red);
>>
>>     vtkDataArray *colorArray = vtkDataArray::SafeDownCast(colors);
>>     colorArray->SetName("ColorsArray");  ////set color array name
>>
>>     vtkSmartPointer<vtkCellArray> triangles
>> =vtkSmartPointer<vtkCellArray>::New();
>>     vtkSmartPointer<vtkTriangle> triangle =
>> vtkSmartPointer<vtkTriangle>::New();
>>     triangle->GetPointIds()->SetId(0, 0);
>>     triangle->GetPointIds()->SetId(1, 1);
>>     triangle->GetPointIds()->SetId(2, 2);
>>     triangles->InsertNextCell(triangle);
>>
>>     vtkSmartPointer<vtkPolyData> polydata =
>> vtkSmartPointer<vtkPolyData>::New();
>>
>>     polydata->SetPoints(points);
>>     polydata->SetPolys(triangles);
>>     polydata->GetCellData()->SetScalars(colors);
>>     ////////////
>>
>>     vesKiwiPolyDataRepresentation::Ptr rep =
>> std::tr1::dynamic_pointer_cast<vesKiwiPolyDataRepresentation>(self->mKiwiApp->dataRepresentations()[0]);
>>     rep->setPolyData(polydata);//(currentPolydata->getPolydata(),
>> newColorLookupTable);
>>     rep->colorByScalars("ColorsArray");  //colorArray->GetName()//(1.0,
>> 0.0, 0.0, 1.0);
>> ////////////////////////////////////////////
>>
>>
>> -   -!  I forgot to cc to mail list.
>>
>>
>> On Tue, Feb 25, 2014 at 11:37 PM, Aashish Chaudhary <
>> aashish.chaudhary at kitware.com> wrote:
>>
>>> Bo,
>>>
>>> If I remember it correctly, you can name your scalar array "foo" and
>>> then pass that array name to the Kiwi (have a look at the documentation for
>>> the exact signature)
>>>
>>> vtkDataArray* da = ....;
>>> da->SetArrayName("foo");
>>>
>>>
>>>
>>> On Tue, Feb 25, 2014 at 9:34 AM, Bo Yu <yubo1983 at gmail.com> wrote:
>>>
>>>> Hi, I am so sorry to interrupt again.
>>>> This time I want to paint the polydata with different colors in each
>>>> region. I found there is a method called
>>>> void vesKiwiPolyDataRepresentation::colorByScalars(const std::string&
>>>> arrayName)
>>>> , which seem similar to the one I used before to set color of a
>>>> polydata in VTK.
>>>> polydata->GetCellData()->SetScalars(vtkDataArray *da).
>>>>
>>>> But why the input is a string called arrayName? If you know, Could you
>>>> tell me how to use this method or give me some simple examples?
>>>>
>>>> Thanks in advance.
>>>>
>>>> Bo Yu
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> | Aashish Chaudhary
>>> | R&D Engineer
>>> | Kitware Inc.
>>> | www.kitware.com
>>>
>>
>>
>> _______________________________________________
>> Ves mailing list
>> Ves at public.kitware.com
>> http://public.kitware.com/cgi-bin/mailman/listinfo/ves
>>
>>
>
>
> --
> Casey B. Goodlett, Ph.D.
> R&D Engineer
> Kitware, Inc. - North Carolina Office
> http://www.kitware.com
> (919) 969-6990 x310
>
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