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

[James Dippner]

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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