[vtkusers] vtkSmartVolumeMapper doesn't properly handle input changes
David E DeMarle
dave.demarle at kitware.com
Tue May 29 12:18:21 EDT 2018
Yes please do file a bug report on gitlab issue tracker.
Thanks
David E DeMarle
Kitware, Inc.
Principal Engineer
21 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-881-4909
On Mon, May 28, 2018 at 7:55 AM, Marc Ruiz Altisent <marc.ruiz+vtk at gmail.com
> wrote:
> Should I create a new issue for this in the bug tracker?
>
> Missatge de Marc Ruiz Altisent <marc.ruiz+vtk at gmail.com> del dia dc., 23
> de maig 2018 a les 19:29:
>
>> Hi everyone,
>>
>> I have found an issue with vtkSmartVolumeMapper. If you create several
>> vtkImageData objects, set one of them as the input of the mapper and
>> render, then you won't be able to render one of the others at a later time:
>> if you set one of the others as input the mapper will keep rendering the
>> first one.
>>
>> The issue is in the method vtkSmartVolumeMapper::ConnectMapperInput. It
>> doesn't pass the original input to its internal mapper, but a shallow copy
>> of it. The first time it will always perform the shallow copy, but
>> afterwards it will only do it if the new input has been modified after
>> creating the previous shallow copy, which is not always the case (e.g. if
>> you create all the data before the first render).
>>
>> Possible workarounds are to call Modified() on the input data when
>> setting a new one or to create a new mapper each time.
>>
>> Below is a sample program (adapted from a couple of examples) to proof
>> the issue. Pressing 1 or 2 alternates between 2 datasets but only the first
>> one is always rendered. Uncommenting the 2 Modified() calls makes it work
>> as expected.
>>
>> #include <vtkSmartPointer.h>
>> #include <vtkSphere.h>
>> #include <vtkBox.h>
>> #include <vtkSampleFunction.h>
>> #include <vtkSmartVolumeMapper.h>
>> #include <vtkColorTransferFunction.h>
>> #include <vtkPiecewiseFunction.h>
>> #include <vtkRenderer.h>
>> #include <vtkRenderWindow.h>
>> #include <vtkRenderWindowInteractor.h>
>> #include <vtkVolumeProperty.h>
>> #include <vtkCamera.h>
>> #include <vtkImageShiftScale.h>
>> #include <vtkImageData.h>
>> #include <vtkPointData.h>
>> #include <vtkDataArray.h>
>> #include <vtkInteractorStyleTrackballCamera.h>
>> #include <vtkObjectFactory.h>
>>
>> // Define interaction style
>> class KeyPressInteractorStyle : public vtkInteractorStyleTrackballCamera
>> {
>> public:
>> static KeyPressInteractorStyle* New();
>> vtkTypeMacro(KeyPressInteractorStyle, vtkInteractorStyleTrackballCam
>> era);
>>
>> virtual void OnKeyPress()
>> {
>> // Get the keypress
>> vtkRenderWindowInteractor *rwi = this->Interactor;
>> std::string key = rwi->GetKeySym();
>>
>> if(key == "1")
>> {
>> mapper->SetInputData(imageData1);
>> //imageData1->Modified();
>> rwi->Render();
>> }
>> else if(key == "2")
>> {
>> mapper->SetInputData(imageData2);
>> //imageData2->Modified();
>> rwi->Render();
>> }
>>
>> // Forward events
>> vtkInteractorStyleTrackballCamera::OnKeyPress();
>> }
>> vtkSmartPointer<vtkVolumeMapper> mapper;
>> vtkSmartPointer<vtkImageData> imageData1, imageData2;
>> };
>> vtkStandardNewMacro(KeyPressInteractorStyle);
>>
>> static void CreateImageData(vtkImageData* im, bool);
>>
>> int main(int argc, char *argv[])
>> {
>> vtkSmartPointer<vtkImageData> imageData =
>> vtkSmartPointer<vtkImageData>::New();
>> vtkSmartPointer<vtkImageData> imageData2 =
>> vtkSmartPointer<vtkImageData>::New();
>>
>> CreateImageData(imageData, true);
>> CreateImageData(imageData2, false);
>>
>> vtkSmartPointer<vtkRenderWindow> renWin =
>> vtkSmartPointer<vtkRenderWindow>::New();
>> vtkSmartPointer<vtkRenderer> ren1 =
>> vtkSmartPointer<vtkRenderer>::New();
>> ren1->SetBackground(0.1,0.4,0.2);
>>
>> renWin->AddRenderer(ren1);
>>
>> renWin->SetSize(301,300); // intentional odd and NPOT width/height
>>
>> vtkSmartPointer<vtkRenderWindowInteractor> iren =
>> vtkSmartPointer<vtkRenderWindowInteractor>::New();
>> iren->SetRenderWindow(renWin);
>>
>> vtkSmartPointer<KeyPressInteractorStyle> style =
>> vtkSmartPointer<KeyPressInteractorStyle>::New();
>> iren->SetInteractorStyle(style);
>> style->SetCurrentRenderer(ren1);
>>
>> renWin->Render(); // make sure we have an OpenGL context.
>>
>> vtkSmartPointer<vtkSmartVolumeMapper> volumeMapper =
>> vtkSmartPointer<vtkSmartVolumeMapper>::New();
>> volumeMapper->SetBlendModeToComposite(); // composite first
>> volumeMapper->SetInputData(imageData);
>> vtkSmartPointer<vtkVolumeProperty> volumeProperty =
>> vtkSmartPointer<vtkVolumeProperty>::New();
>> volumeProperty->ShadeOff();
>> volumeProperty->SetInterpolationType(VTK_LINEAR_INTERPOLATION);
>>
>> style->mapper = volumeMapper;
>> style->imageData1 = imageData;
>> style->imageData2 = imageData2;
>>
>> vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity =
>> vtkSmartPointer<vtkPiecewiseFunction>::New();
>> compositeOpacity->AddPoint(0.0,0.0);
>> compositeOpacity->AddPoint(80.0,1.0);
>> compositeOpacity->AddPoint(80.1,0.0);
>> compositeOpacity->AddPoint(255.0,0.0);
>> volumeProperty->SetScalarOpacity(compositeOpacity); // composite first.
>>
>> vtkSmartPointer<vtkColorTransferFunction> color =
>> vtkSmartPointer<vtkColorTransferFunction>::New();
>> color->AddRGBPoint(0.0 ,0.0,0.0,1.0);
>> color->AddRGBPoint(40.0 ,1.0,0.0,0.0);
>> color->AddRGBPoint(255.0,1.0,1.0,1.0);
>> volumeProperty->SetColor(color);
>>
>> vtkSmartPointer<vtkVolume> volume =
>> vtkSmartPointer<vtkVolume>::New();
>> volume->SetMapper(volumeMapper);
>> volume->SetProperty(volumeProperty);
>> ren1->AddViewProp(volume);
>> ren1->ResetCamera();
>>
>> // Render composite. In default mode. For coverage.
>> renWin->Render();
>>
>> iren->Start();
>>
>> return EXIT_SUCCESS;
>> }
>>
>> void CreateImageData(vtkImageData* imageData, bool spherical)
>> {
>> vtkSmartPointer<vtkImplicitFunction> implicitFunction;
>>
>> if (spherical)
>> {
>> vtkSmartPointer<vtkSphere> sphere =
>> vtkSmartPointer<vtkSphere>::New();
>> sphere->SetRadius(0.1);
>> sphere->SetCenter(0.0,0.0,0.0);
>> implicitFunction = sphere;
>> }
>> else
>> {
>> vtkSmartPointer<vtkBox> box =
>> vtkSmartPointer<vtkBox>::New();
>> box->SetBounds(-0.1, 0.1, -0.1, 0.1, -0.1, 0.1);
>> implicitFunction = box;
>> }
>>
>> vtkSmartPointer<vtkSampleFunction> sampleFunction =
>> vtkSmartPointer<vtkSampleFunction>::New();
>> sampleFunction->SetImplicitFunction(implicitFunction);
>> sampleFunction->SetOutputScalarTypeToDouble();
>> sampleFunction->SetSampleDimensions(127,127,127); // intentional NPOT
>> dimensions.
>> sampleFunction->SetModelBounds(-1.0,1.0,-1.0,1.0,-1.0,1.0);
>> sampleFunction->SetCapping(false);
>> sampleFunction->SetComputeNormals(false);
>> sampleFunction->SetScalarArrayName("values");
>> sampleFunction->Update();
>>
>> vtkDataArray* a = sampleFunction->GetOutput()->
>> GetPointData()->GetScalars("values");
>> double range[2];
>> a->GetRange(range);
>>
>> vtkSmartPointer<vtkImageShiftScale> t =
>> vtkSmartPointer<vtkImageShiftScale>::New();
>> t->SetInputConnection(sampleFunction->GetOutputPort());
>>
>> t->SetShift(-range[0]);
>> double magnitude=range[1]-range[0];
>> if(magnitude==0.0)
>> {
>> magnitude=1.0;
>> }
>> t->SetScale(255.0/magnitude);
>> t->SetOutputScalarTypeToUnsignedChar();
>>
>> t->Update();
>>
>> imageData->ShallowCopy(t->GetOutput());
>> }
>>
>
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