vtk9.0.1+Qt5.13手动创建四窗口（MPR+3D）

由于vtk9不在有vtk7那样的插件，可以直接拖动到QWidget中，但我们可以手动创建，其实效果是相同的。

class vtkResliceCursorCallback : public vtkCommand
{
public:
	static vtkResliceCursorCallback *New()
	{
		return new vtkResliceCursorCallback;
	}

	void Execute(vtkObject *caller, unsigned long ev,
		void *callData) override
	{

		if (ev == vtkResliceCursorWidget::WindowLevelEvent ||
			ev == vtkCommand::WindowLevelEvent ||
			ev == vtkResliceCursorWidget::ResliceThicknessChangedEvent)
		{
			// Render everything
			for (int i = 0; i < 3; i++)
			{
				this->RCW[i]->Render();
			}
			this->IPW[0]->GetInteractor()->GetRenderWindow()->Render();
			return;
		}

		vtkImagePlaneWidget* ipw =
			dynamic_cast(caller);
		if (ipw)
		{
			double* wl = static_cast(callData);

			if (ipw == this->IPW[0])
			{
				this->IPW[1]->SetWindowLevel(wl[0], wl[1], 1);
				this->IPW[2]->SetWindowLevel(wl[0], wl[1], 1);
			}
			else if (ipw == this->IPW[1])
			{
				this->IPW[0]->SetWindowLevel(wl[0], wl[1], 1);
				this->IPW[2]->SetWindowLevel(wl[0], wl[1], 1);
			}
			else if (ipw == this->IPW[2])
			{
				this->IPW[0]->SetWindowLevel(wl[0], wl[1], 1);
				this->IPW[1]->SetWindowLevel(wl[0], wl[1], 1);
			}
		}

		vtkResliceCursorWidget *rcw = dynamic_cast<
			vtkResliceCursorWidget *>(caller);
		if (rcw)
		{
			vtkResliceCursorLineRepresentation *rep = dynamic_cast<
				vtkResliceCursorLineRepresentation *>(rcw->GetRepresentation());
			// Although the return value is not used, we keep the get calls
			// in case they had side-effects
			rep->GetResliceCursorActor()->GetCursorAlgorithm()->GetResliceCursor();
			for (int i = 0; i < 3; i++)
			{
				vtkPlaneSource *ps = static_cast(
					this->IPW[i]->GetPolyDataAlgorithm());
				ps->SetOrigin(this->RCW[i]->GetResliceCursorRepresentation()->
					GetPlaneSource()->GetOrigin());
				ps->SetPoint1(this->RCW[i]->GetResliceCursorRepresentation()->
					GetPlaneSource()->GetPoint1());
				ps->SetPoint2(this->RCW[i]->GetResliceCursorRepresentation()->
					GetPlaneSource()->GetPoint2());

				// If the reslice plane has modified, update it on the 3D widget
				this->IPW[i]->UpdatePlacement();
			}
		}

		// Render everything
		for (int i = 0; i < 3; i++)
		{
			this->RCW[i]->Render();
		}
		this->IPW[0]->GetInteractor()->GetRenderWindow()->Render();
	}

	vtkResliceCursorCallback() {}
	vtkImagePlaneWidget* IPW[3];
	vtkResliceCursorWidget *RCW[3];
};
 

TestVTK9FourViewer::TestVTK9FourViewer(QWidget *parent)
    : QWidget(parent)
{
    ui.setupUi(this);
	m_gridLayout = new QGridLayout(this);

	QRect rt = this->geometry();
	m_gridLayout->setGeometry(rt);
	for (size_t i = 0; i < 4; i++)
	{
		m_pViewWindow[i] = new WeVTKOpenGLWIdget(this);
	}

	for (size_t i = 0; i < 3; i++)
	{
		m_pSlicerViewer[i] = vtkSmartPointer::New();
		m_renderWindow[i] = vtkSmartPointer::New();
		m_pSlicerViewer[i]->SetRenderWindow(m_renderWindow[i]);
	}

	m_gridLayout->addWidget(m_pViewWindow[0], 0, 0);
	m_gridLayout->addWidget(m_pViewWindow[1], 0, 1);
	m_gridLayout->addWidget(m_pViewWindow[2], 1, 0);
	m_gridLayout->addWidget(m_pViewWindow[3], 1, 1);
	vtkSmartPointer reader = vtkSmartPointer::New();
	reader->SetDirectoryName("D:/imageData/2013-06-04_dcm");
	reader->Update();
	int imageDims[3];
	reader->GetOutput()->GetDimensions(imageDims);
	m_pViewWindow[0]->init(reader->GetOutput());
	m_pViewWindow[1]->init(reader->GetOutput());
	m_pViewWindow[2]->init(reader->GetOutput());


	m_pViewWindow[0]->setRenderWindow(m_pSlicerViewer[0]->GetRenderWindow());
	m_pSlicerViewer[0]->SetupInteractor(m_pViewWindow[0]->renderWindow()->GetInteractor());

	m_pViewWindow[1]->setRenderWindow(m_pSlicerViewer[1]->GetRenderWindow());
	m_pSlicerViewer[1]->SetupInteractor(m_pViewWindow[1]->renderWindow()->GetInteractor());

	m_pViewWindow[2]->setRenderWindow(m_pSlicerViewer[2]->GetRenderWindow());
	m_pSlicerViewer[2]->SetupInteractor(m_pViewWindow[2]->renderWindow()->GetInteractor());

	for (int i = 0; i < 3; i++)
	{
		// make them all share the same reslice cursor object.
		vtkResliceCursorLineRepresentation *rep = vtkResliceCursorLineRepresentation::SafeDownCast(m_pSlicerViewer[i]->GetResliceCursorWidget()->GetRepresentation());
		m_pSlicerViewer[i]->SetResliceCursor(m_pSlicerViewer[0]->GetResliceCursor());

		rep->GetResliceCursorActor()->GetCursorAlgorithm()->SetReslicePlaneNormal(i);

		m_pSlicerViewer[i]->SetInputData(reader->GetOutput());
		m_pSlicerViewer[i]->SetSliceOrientation(i);
		m_pSlicerViewer[i]->SetResliceModeToAxisAligned();
	}

	vtkSmartPointer picker = vtkSmartPointer::New();
	picker->SetTolerance(0.005);

	vtkSmartPointer ipwProp = vtkSmartPointer::New();

	vtkSmartPointer< vtkRenderer > ren = vtkSmartPointer< vtkRenderer >::New();

	vtkNew renderWindow;
	m_pViewWindow[3]->setRenderWindow(renderWindow);
	m_pViewWindow[3]->renderWindow()->AddRenderer(ren);
	vtkRenderWindowInteractor *iren = m_pViewWindow[3]->interactor();

	for (int i = 0; i < 3; i++)
	{
		planeWidget[i] = vtkSmartPointer::New();
		planeWidget[i]->SetInteractor(iren);
		planeWidget[i]->SetPicker(picker);
		planeWidget[i]->RestrictPlaneToVolumeOn();
		double color[3] = { 0, 0, 0 };
		color[i] = 1;
		planeWidget[i]->GetPlaneProperty()->SetColor(color);

		color[0] /= 4.0;
		color[1] /= 4.0;
		color[2] /= 4.0;
		m_pSlicerViewer[i]->GetRenderer()->SetBackground(color);

		planeWidget[i]->SetTexturePlaneProperty(ipwProp);
		planeWidget[i]->TextureInterpolateOff();
		planeWidget[i]->SetResliceInterpolateToLinear();
		planeWidget[i]->SetInputConnection(reader->GetOutputPort());
		planeWidget[i]->SetPlaneOrientation(i);
		planeWidget[i]->SetSliceIndex(imageDims[i] / 2);
		planeWidget[i]->DisplayTextOn();
		planeWidget[i]->SetDefaultRenderer(ren);
		planeWidget[i]->SetWindowLevel(1358, -27);
		planeWidget[i]->On();
		planeWidget[i]->InteractionOn();
	}

	vtkSmartPointer cbk = vtkSmartPointer::New();

	for (int i = 0; i < 3; i++)
	{
		cbk->IPW[i] = planeWidget[i];
		cbk->RCW[i] = m_pSlicerViewer[i]->GetResliceCursorWidget();
		m_pSlicerViewer[i]->GetResliceCursorWidget()->AddObserver(
			vtkResliceCursorWidget::ResliceAxesChangedEvent, cbk);
		m_pSlicerViewer[i]->GetResliceCursorWidget()->AddObserver(
			vtkResliceCursorWidget::WindowLevelEvent, cbk);
		m_pSlicerViewer[i]->GetResliceCursorWidget()->AddObserver(
			vtkResliceCursorWidget::ResliceThicknessChangedEvent, cbk);
		m_pSlicerViewer[i]->GetResliceCursorWidget()->AddObserver(
			vtkResliceCursorWidget::ResetCursorEvent, cbk);
		m_pSlicerViewer[i]->GetInteractorStyle()->AddObserver(
			vtkCommand::WindowLevelEvent, cbk);

		// Make them all share the same color map.
		m_pSlicerViewer[i]->SetLookupTable(m_pSlicerViewer[0]->GetLookupTable());
		planeWidget[i]->GetColorMap()->SetLookupTable(m_pSlicerViewer[0]->GetLookupTable());
		//planeWidget[i]->GetColorMap()->SetInput(riw[i]->GetResliceCursorWidget()->GetResliceCursorRepresentation()->GetColorMap()->GetInput());
		planeWidget[i]->SetColorMap(m_pSlicerViewer[i]->GetResliceCursorWidget()->GetResliceCursorRepresentation()->GetColorMap());

	}
 

}