[vtkusers] [other] Rendering 2D image and points

[Pascale Beliveau]

Hi James,

   Unfortunately, if I set the visibility to false, the points are not
rendered at all. I made the test rendering only the points with visibility
set to false and true and this will not help for the transparancy.

To set the opacity, I used vtkImageBlend for the image. I also set the alpha
factor for the points using the lookuptable but it did not help. I can still
only render or the image, or the points and not both at the same time.

 If you have other suggestions, I would appreciate it! I still have the
problem,

Pascale



On 8/28/08, James Dippner <jdippner at informetric.com> wrote:
>
> You might try setting the cell visibility on the points actor to false, you
> may also try setting the opacity for the same actor.
>
>
>
> Pascale Beliveau wrote:
>
>> Hi vtkusers,
>>     I want to try a simple task: show an image (jpg) and see points over
>> it. I have done the following code but the image is shown darker than it
>> should. When rendered alone, the image has the correct intensities. Here is
>> what I did:
>>  - create polydata from points and cells
>> - create PolyDataMapper, Actor and Renderer for polydata
>> - create ImageMapper, Actor2D and Renderer for image (vtkImageData)
>> - create RenderWindow and add both renderer for polydata and for image
>>  Is there something I'm missing, or do I add both images incorectly to the
>> RenderWindow? I'm a bit puzzled by this effect and did not find anything
>> helpfull on the mailing list.
>>  Thanks in advance for your help,
>> Pascale
>>   The following is the code I created:
>>  // create set of points that will deform image
>> vtkPoints * Points = vtkPoints::New();
>> Points->SetNumberOfPoints(2);
>> Points->SetPoint(0,1,1,1);
>> Points->SetPoint(1,10,10,10);
>> vtkCellArray * Cells = vtkCellArray::New();
>> Cells->InsertNextCell(2);
>> Cells->InsertCellPoint(0);
>> Cells->InsertCellPoint(1);
>>
>> vtkPolyData * PolyData = vtkPolyData::New();
>> PolyData->SetPoints(Points);
>> PolyData->SetVerts(Cells);
>>
>> // create image viewer
>> vtkImageMapper * MapImage = vtkImageMapper::New();
>> MapImage->SetInput(Image);
>> vtkActor2D * ImActor = vtkActor2D::New();
>> ImActor->SetMapper(MapImage);
>> vtkRenderer * ImRenderer = vtkRenderer::New();
>> ImRenderer->AddActor2D(ImActor);
>>
>> vtkRenderWindowInteractor * Interactor = vtkRenderWindowInteractor::New();
>>
>> // create viewer for points
>> vtkPolyDataMapper * Mapper = vtkPolyDataMapper::New();
>> Mapper->SetInput(PolyData);
>> vtkActor * Actor = vtkActor::New();
>> Actor->SetMapper(Mapper);
>> vtkRenderer * Renderer = vtkRenderer::New();
>> Renderer->AddViewProp(Actor);
>>   // add both to main render window
>> vtkRenderWindow * RenderWindow = vtkRenderWindow::New();
>> RenderWindow->SetSize(400,600);
>> RenderWindow->SetInteractor(Interactor);
>> RenderWindow->AddRenderer(Renderer);
>> RenderWindow->AddRenderer(ImRenderer);
>> RenderWindow->Render();
>> Interactor->Start();
>> ------------------------------------------------------------------------
>>
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>
> --
>
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