[Ves] How to color polydata with Scalars in VES
Bo Yu
yubo1983 at gmail.com
Mon Mar 3 00:42:55 EST 2014
Dear Aashish,
Thank you very much for all you suggestions as I can draw model with given
point index now. However, I also want to color the polydata cell by cell.
I try to use vtkCellDataToPointData suggested by you and Casey, I refer
some examples and docs, but still I can not make it work.
The basic code I wrote about this is list below. Could you help me check
what's wrong with that? Thank you very much.
////////////////////////////////////////////////////////////////////////////////////
vtkSmartPointer<vtkCellDataToPointData> c2p = vtkCellDataToPointData::New();
c2p->PassCellDataOn();
c2p->SetInputData(currentModel->getPolydata()); //here is the input
vtkPolydata
c2p->Update();
vtkSmartPointer<vtkPolyData> pd = c2p->GetPolyDataOutput();
pd->GetPointData()->SetScalars(colorTable);//color works like on each
vertexes and scalar, color table is an vtkUnsignedCharArray which contains
same tuples as vertexes number.
//pd->GetCellData()->SetScalars(colorTable);//no color at all, color table
is an vtkUnsignedCharArray which contains same tuples as cells number.
vesKiwiPolyDataRepresentation::Ptr rep =
std::tr1::dynamic_pointer_cast<vesKiwiPolyDataRepresentation>(self->mKiwiApp->dataRepresentations()[0]);
rep->colorByRGBArray();
rep->setPolyData(pd);
////////////////////////////////////////////////////////////////////////////////////
Sincerely yours,
Yu Bo
On Fri, Feb 28, 2014 at 12:00 AM, Aashish Chaudhary <
aashish.chaudhary at kitware.com> wrote:
> Bo,
>
>
> On Thu, Feb 27, 2014 at 12:22 AM, Bo Yu <yubo1983 at gmail.com> wrote:
>
>> 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.
>>
>
> Yes.
>
>
>> 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?
>>
>
> So basically you want to have color per face (or cell) rather than color
> per vertices right? In that can you can run your polydata through
> vtkCellDataToPointData filter as s
> suggested by Casey earlier. I have a branch that does it internally when
> you sent the polydata on the representation that will be available in
> master tomorrow if all goes well.
>
>
>> Sorry but I know little about this, is there some documents about how
>> to achieve this goal?
>> Thank you very much.
>>
>
> http://www.vtk.org/doc/nightly/html/classvtkCellDataToPointData.html
>
>>
>> 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
>>>
>>
>>
>
>
> --
> | Aashish Chaudhary
> | R&D Engineer
> | Kitware Inc.
> | www.kitware.com
>
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