VTK volume rendering crop

#include "stdafx.h"
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);
VTK_MODULE_INIT(vtkRenderingVolumeOpenGL2);

#include <vtkSmartPointer.h>  
#include <vtkStructuredPoints.h>//vtkStructuredPointsReader* -> vtkGPUVolumeRayCastMapper*  
#include <vtkStructuredPointsReader.h>  
#include <vtkGPUVolumeRayCastMapper.h>  
#include <vtkVolumeProperty.h>  
#include <vtkPiecewiseFunction.h>  
#include <vtkColorTransferFunction.h>  
#include <vtkVolume.h>  
#include <vtkRenderer.h>  
#include <vtkRenderWindow.h>  
#include <vtkRenderWindowInteractor.h>  
#include <vtkCamera.h>  

int _tmain(int argc, _TCHAR* argv[])
{
	vtkSmartPointer<vtkStructuredPointsReader> reader =
		vtkSmartPointer<vtkStructuredPointsReader>::New();
	reader->SetFileName("../mummy.128.vtk");
	reader->Update();

	vtkSmartPointer<vtkGPUVolumeRayCastMapper> origMapper =
		vtkSmartPointer<vtkGPUVolumeRayCastMapper>::New();
	origMapper->SetInputData(reader->GetOutput());


	vtkSmartPointer<vtkGPUVolumeRayCastMapper> volumeMapper =
		vtkSmartPointer<vtkGPUVolumeRayCastMapper>::New();
	volumeMapper->SetInputData(reader->GetOutput());
	volumeMapper->SetCropping(1);//开启Cropping功能  
	volumeMapper->SetCroppingRegionPlanes(50, 150, 50, 200, 50, 150);
	volumeMapper->SetCroppingRegionFlags(0x0002000);
	/*****************************************************************/
	//设置体绘制相关属性  
	vtkSmartPointer<vtkVolumeProperty> volumeProperty =
		vtkSmartPointer<vtkVolumeProperty>::New();
	volumeProperty->SetInterpolationTypeToLinear(); //设置线性插值方式  
	volumeProperty->ShadeOn();//开启阴影属性  
	volumeProperty->SetAmbient(0.4);//设置环境温度  
	volumeProperty->SetDiffuse(0.6);//设置漫反射系数  
	volumeProperty->SetSpecular(0.2);//设置镜面反射系数  
	//添加灰度不透明度属性  
	vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	compositeOpacity->AddPoint(70, 0.0);
	compositeOpacity->AddPoint(90, 0.4);
	compositeOpacity->AddPoint(180, 0.6);
	volumeProperty->SetScalarOpacity(compositeOpacity);
	//添加梯度不同明度属性  
	vtkSmartPointer<vtkPiecewiseFunction> gradientOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	gradientOpacity->AddPoint(10, 0.0);
	gradientOpacity->AddPoint(90, 0.5);
	gradientOpacity->AddPoint(100, 1.0);
	volumeProperty->SetGradientOpacity(gradientOpacity);
	//添加颜色传输  
	vtkSmartPointer<vtkColorTransferFunction> color =
		vtkSmartPointer<vtkColorTransferFunction>::New();
	color->AddRGBPoint(0, 0, 0, 0);
	color->AddRGBPoint(64, 1.0, 0.52, 0.3);
	color->AddRGBPoint(190.0, 1.00, 1.00, 1.00);
	color->AddRGBPoint(220.0, 0.20, 0.20, 0.20);
	volumeProperty->SetColor(color);
	/***********************************************************/
	//渲染管道  
	vtkSmartPointer<vtkVolume> origVolume =
		vtkSmartPointer<vtkVolume>::New();
	origVolume->SetMapper(origMapper);
	origVolume->SetProperty(volumeProperty);


	vtkSmartPointer<vtkVolume> croppingVolume =
		vtkSmartPointer<vtkVolume>::New();
	croppingVolume->SetMapper(volumeMapper);
	croppingVolume->SetProperty(volumeProperty);


	/////////////////////////////////  
	double origView[4] = { 0, 0, 0.5, 1 };
	double croppingView[4] = { 0.5, 0, 1, 1 };
	vtkSmartPointer<vtkRenderer> origRender =
		vtkSmartPointer<vtkRenderer>::New();
	origRender->AddVolume(origVolume);
	origRender->SetBackground(1, 1, 0);
	origRender->SetViewport(origView);


	vtkSmartPointer<vtkRenderer> croppingRender =
		vtkSmartPointer<vtkRenderer>::New();
	croppingRender->AddVolume(croppingVolume);
	croppingRender->SetBackground(0, 1, 0);
	croppingRender->SetViewport(croppingView);
	///////////////////////////////////  
	vtkSmartPointer<vtkRenderWindow> rw =
		vtkSmartPointer<vtkRenderWindow>::New();
	rw->AddRenderer(origRender);
	rw->AddRenderer(croppingRender);
	rw->SetWindowName("Cropping Volume");
	rw->SetSize(640, 320);


	vtkSmartPointer<vtkRenderWindowInteractor> rwi =
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	rwi->SetRenderWindow(rw);


	origRender->GetActiveCamera()->SetPosition(0, -1, 0);
	origRender->GetActiveCamera()->SetFocalPoint(0, 0, 0);
	origRender->GetActiveCamera()->SetViewUp(0, 0, 1);
	origRender->GetActiveCamera()->Azimuth(30);
	origRender->GetActiveCamera()->Elevation(30);
	origRender->ResetCamera();
	croppingRender->SetActiveCamera(origRender->GetActiveCamera());

	rw->Render();
	rwi->Start();
	return 0;
}