基于C++的VTK8学习笔记4（VTK体绘制）

VTK资料分享：张晓东的《VTK图形图像开发进阶》全套资料（包含书籍电子版，配套每章节所有源码、实现效果图和工程配置文件）

水灵VTK学习全套资料（包含全部视频、PPT、源码和每个项目对应的工程配置文件CmakeLists.txt）

水灵VT视频在线观看
本文参考的主要是张晓东的《VTK图形图像开发进阶》和水灵的视频Study VTK Together。使用的平台是VS2019+VTK8.2

 

VTK系列目录：

1 VTK基本概念

2 VTK图像处理

3 VTK图形处理

4 VTK体绘制

 

4 VTK体绘制

实例64：体绘制管线（光线投影法体绘制） 实例65：最大密度投影法体绘制 实例66：GPU加速光线投影体绘制 实例67：裁剪 实例68：透明度

 

实例64：体绘制管线（光线投影法体绘制）

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkRenderingVolumeOpenGL2); //错误：no override found for 'vtkRayCastImageDisplayHelper'.
VTK_MODULE_INIT(vtkRenderingFreeType);
VTK_MODULE_INIT(vtkInteractionStyle);

#include <vtkSmartPointer.h>
#include <vtkStructuredPoints.h>
#include <vtkStructuredPointsReader.h>
#include <vtkFixedPointVolumeRayCastMapper.h>
#include <vtkColorTransferFunction.h>
#include <vtkPiecewiseFunction.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkVolumeProperty.h>
#include <vtkAxesActor.h>
#include <vtkOrientationMarkerWidget.h>

int main(int argc, char* argv[])
{
	vtkSmartPointer<vtkStructuredPointsReader> reader =
		vtkSmartPointer<vtkStructuredPointsReader>::New();
	reader->SetFileName("C:\\Users\\Administrator\\Desktop\\VTK2\\hellovtk\\vtk_图像处理学习\\第七章_VTK体绘制\\data\\mummy.128.vtk");
	reader->Update();


	vtkSmartPointer<vtkFixedPointVolumeRayCastMapper> volumeMapper =
		vtkSmartPointer<vtkFixedPointVolumeRayCastMapper>::New();
	volumeMapper->SetInputData(reader->GetOutput());

	//设置光线采样距离
	//volumeMapper->SetSampleDistance(volumeMapper->GetSampleDistance()*4);
	//设置图像采样步长
	//volumeMapper->SetAutoAdjustSampleDistances(0);
	//volumeMapper->SetImageSampleDistance(4);
	/*************************************************************************/
	vtkSmartPointer<vtkVolumeProperty> volumeProperty =
		vtkSmartPointer<vtkVolumeProperty>::New();
	volumeProperty->SetInterpolationTypeToLinear();
	volumeProperty->ShadeOn();  //打开或者关闭阴影测试
	volumeProperty->SetAmbient(0.4);
	volumeProperty->SetDiffuse(0.6);  //漫反射
	volumeProperty->SetSpecular(0.2); //镜面反射
	//设置不透明度
	vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	compositeOpacity->AddPoint(70, 0.00);
	compositeOpacity->AddPoint(90, 0.40);
	compositeOpacity->AddPoint(180, 0.60);
	volumeProperty->SetScalarOpacity(compositeOpacity); //设置不透明度传输函数
	//compositeOpacity->AddPoint(120,  0.00);//测试隐藏部分数据,对比不同的设置
	//compositeOpacity->AddPoint(180,  0.60);
	//volumeProperty->SetScalarOpacity(compositeOpacity);
	//设置梯度不透明属性
	vtkSmartPointer<vtkPiecewiseFunction> volumeGradientOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	volumeGradientOpacity->AddPoint(10, 0.0);
	volumeGradientOpacity->AddPoint(90, 0.5);
	volumeGradientOpacity->AddPoint(100, 1.0);
	volumeProperty->SetGradientOpacity(volumeGradientOpacity);//设置梯度不透明度效果对比
	//设置颜色属性
	vtkSmartPointer<vtkColorTransferFunction> color =
		vtkSmartPointer<vtkColorTransferFunction>::New();
	color->AddRGBPoint(0.000, 0.00, 0.00, 0.00);
	color->AddRGBPoint(64.00, 1.00, 0.52, 0.30);
	color->AddRGBPoint(190.0, 1.00, 1.00, 1.00);
	color->AddRGBPoint(220.0, 0.20, 0.20, 0.20);
	volumeProperty->SetColor(color);
	/********************************************************************************/
	vtkSmartPointer<vtkVolume> volume =
		vtkSmartPointer<vtkVolume>::New();
	volume->SetMapper(volumeMapper);
	volume->SetProperty(volumeProperty);

	vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();
	ren->SetBackground(0, 1, 0);
	ren->AddVolume(volume);

	vtkSmartPointer<vtkRenderWindow> rw = vtkSmartPointer<vtkRenderWindow>::New();
	rw->AddRenderer(ren);
	rw->SetSize(640, 480);
	rw->Render();
	rw->SetWindowName("VolumeRendering PipeLine");

	vtkSmartPointer<vtkRenderWindowInteractor> rwi =
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	rwi->SetRenderWindow(rw);
	/********************************************************************************/
	//vtkSmartPointer<vtkAxesActor> axes = vtkSmartPointer<vtkAxesActor>::New();
	//axes->SetScale(10);
	//vtkSmartPointer<vtkOrientationMarkerWidget> widget =
	//	vtkSmartPointer<vtkOrientationMarkerWidget>::New();
	//widget->SetOutlineColor(1, 1, 1);
	//widget->SetViewport(0, 0, 0.2, 0.2);
	//widget->SetOrientationMarker(axes);
	//widget->SetInteractor(rwi);
	//widget->SetEnabled(1);
	//widget->InteractiveOn();

	ren->ResetCamera();
	rw->Render();
	rwi->Start();

	return 0;
}

 

                          

实例65：最大密度投影法体绘制

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkRenderingVolumeOpenGL2); //错误：no override found for 'vtkRayCastImageDisplayHelper'.
VTK_MODULE_INIT(vtkRenderingFreeType);
VTK_MODULE_INIT(vtkInteractionStyle);

#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkStructuredPoints.h>
#include <vtkStructuredPointsReader.h>
#include <vtkFixedPointVolumeRayCastMIPHelper.h>
#include <vtkFixedPointVolumeRayCastMapper.h>
#include <vtkColorTransferFunction.h>
#include <vtkPiecewiseFunction.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkVolumeProperty.h>
#include <vtkAxesActor.h>
#include <vtkImageShiftScale.h>
#include <vtkImageCast.h>

//测试：../data/mummy.128.vtk
int main(int argc, char *argv[])
{
	vtkSmartPointer<vtkStructuredPointsReader> reader =
		vtkSmartPointer<vtkStructuredPointsReader>::New();

	reader->SetFileName("C:\\Users\\Administrator\\Desktop\\VTK2\\hellovtk\\vtk_图像处理学习\\第七章_VTK体绘制\\data\\mummy.128.vtk");
	reader->Update();

	vtkSmartPointer<vtkFixedPointVolumeRayCastMIPHelper> rayCastFun =
		vtkSmartPointer<vtkFixedPointVolumeRayCastMIPHelper>::New();

	vtkSmartPointer<vtkFixedPointVolumeRayCastMapper> volumeMapper =
		vtkSmartPointer<vtkFixedPointVolumeRayCastMapper>::New();
	volumeMapper->SetInputData(reader->GetOutput());
	//volumeMapper->Set
		//SetVolumeRayCastMapperFunction(rayCastFun);//必须设置，否则出错

	vtkSmartPointer<vtkVolumeProperty> volumeProperty = 
		vtkSmartPointer<vtkVolumeProperty>::New();
	volumeProperty->SetInterpolationTypeToLinear();
	volumeProperty->ShadeOn();
	volumeProperty->SetAmbient(0.4);
	volumeProperty->SetDiffuse(0.6);
	volumeProperty->SetSpecular(0.2);

	vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity = 
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	compositeOpacity->AddPoint(70,   0.00);
	compositeOpacity->AddPoint(90,   0.40);
	compositeOpacity->AddPoint(180,  0.60);
	volumeProperty->SetScalarOpacity(compositeOpacity);

	vtkSmartPointer<vtkColorTransferFunction> color = 
		vtkSmartPointer<vtkColorTransferFunction>::New();
	color->AddRGBPoint(0.000,  0.00, 0.00, 0.00);
	color->AddRGBPoint(64.00,  1.00, 0.52, 0.30);
	color->AddRGBPoint(190.0,  1.00, 1.00, 1.00);
	color->AddRGBPoint(220.0,  0.20, 0.20, 0.20);
	volumeProperty->SetColor(color);

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

	vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();
	ren->SetBackground(1.0, 1.0, 1.0);
	ren->AddVolume( volume ); 

	vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New();
	renWin->AddRenderer(ren);
	renWin->SetSize(640, 480);
	renWin->Render();
	renWin->SetWindowName("MIPVolRenderingApp");

	vtkSmartPointer<vtkRenderWindowInteractor> iren = 
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	iren->SetRenderWindow(renWin);
	ren->ResetCamera();

	renWin->Render();
	iren->Start();

	return EXIT_SUCCESS;
}

实例66：GPU加速光线投影体绘制

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

#include <vtkSmartPointer.h>
#include <vtkStructuredPoints.h>
#include <vtkStructuredPointsReader.h>
#include <vtkGPUVolumeRayCastMapper.h>
#include <vtkColorTransferFunction.h>
#include <vtkPiecewiseFunction.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkVolumeProperty.h>
//#include <vtkVolumeRayCastIsosurfaceFunction.h>

int main(int argc, char* argv[])
{
	vtkSmartPointer<vtkStructuredPointsReader> reader =
		vtkSmartPointer<vtkStructuredPointsReader>::New();
	reader->SetFileName("C:\\Users\\Administrator\\Desktop\\VTK2\\hellovtk\\vtk_图像处理学习\\第七章_VTK体绘制\\data\\mummy.128.vtk");
	reader->Update();


	vtkSmartPointer<vtkGPUVolumeRayCastMapper> volumeMapper =
		vtkSmartPointer<vtkGPUVolumeRayCastMapper>::New();
	volumeMapper->SetInputData(reader->GetOutput());;
	volumeMapper->SetSampleDistance(volumeMapper->GetSampleDistance() / 2);	//设置光线采样距离
	//volumeMapper->SetAutoAdjustSampleDistances(0);//设置图像采样步长
	//volumeMapper->SetImageSampleDistance(4);
	/*************************************************************************/
	vtkSmartPointer<vtkVolumeProperty> volumeProperty =
		vtkSmartPointer<vtkVolumeProperty>::New();
	volumeProperty->SetInterpolationTypeToLinear();
	volumeProperty->ShadeOn();  //打开或者关闭阴影测试
	volumeProperty->SetAmbient(0.4);
	volumeProperty->SetDiffuse(0.6);  //漫反射
	volumeProperty->SetSpecular(0.2); //镜面反射
	//设置不透明度
	vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	compositeOpacity->AddPoint(70, 0.00);
	compositeOpacity->AddPoint(90, 0.40);
	compositeOpacity->AddPoint(180, 0.60);
	volumeProperty->SetScalarOpacity(compositeOpacity); //设置不透明度传输函数
	//设置梯度不透明属性
	vtkSmartPointer<vtkPiecewiseFunction> volumeGradientOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	volumeGradientOpacity->AddPoint(10, 0.0);
	volumeGradientOpacity->AddPoint(90, 0.5);
	volumeGradientOpacity->AddPoint(100, 1.0);
	volumeProperty->SetGradientOpacity(volumeGradientOpacity);//设置梯度不透明度效果对比
	//设置颜色属性
	vtkSmartPointer<vtkColorTransferFunction> color =
		vtkSmartPointer<vtkColorTransferFunction>::New();
	color->AddRGBPoint(0.000, 0.00, 0.00, 0.00);
	color->AddRGBPoint(64.00, 1.00, 0.52, 0.30);
	color->AddRGBPoint(190.0, 1.00, 1.00, 1.00);
	color->AddRGBPoint(220.0, 0.20, 0.20, 0.20);
	volumeProperty->SetColor(color);
	/********************************************************************************/
	vtkSmartPointer<vtkVolume> volume =
		vtkSmartPointer<vtkVolume>::New();
	volume->SetMapper(volumeMapper);
	volume->SetProperty(volumeProperty);

	vtkSmartPointer<vtkRenderer> ren = vtkSmartPointer<vtkRenderer>::New();
	ren->SetBackground(0, 1, 0);
	ren->AddVolume(volume);

	vtkSmartPointer<vtkRenderWindow> rw = vtkSmartPointer<vtkRenderWindow>::New();
	rw->AddRenderer(ren);
	rw->SetSize(640, 480);
	rw->Render();
	rw->SetWindowName("VolumeRendering");

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

	ren->ResetCamera();
	rw->Render();
	rwi->Start();

	return 0;
}

实例67：裁剪

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


#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 main()
{
	vtkSmartPointer<vtkStructuredPointsReader> reader =
		vtkSmartPointer<vtkStructuredPointsReader>::New();
	reader->SetFileName("C:\\Users\\Administrator\\Desktop\\VTK2\\hellovtk\\vtk_图像处理学习\\第七章_VTK体绘制\\data\\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;
}

实例68：透明度

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

#include <vtkSmartPointer.h>
#include <vtkStructuredPointsReader.h>
#include <vtkStructuredPoints.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 main()
{
	vtkSmartPointer<vtkStructuredPointsReader> reader =
		vtkSmartPointer<vtkStructuredPointsReader>::New();
	reader->SetFileName("C:\\Users\\Administrator\\Desktop\\VTK2\\hellovtk\\vtk_图像处理学习\\第七章_VTK体绘制\\data\\mummy.128.vtk");
	reader->Update();

	vtkSmartPointer<vtkGPUVolumeRayCastMapper> volumeMapper1 =
		vtkSmartPointer<vtkGPUVolumeRayCastMapper>::New();
	volumeMapper1->SetInputData(reader->GetOutput());

	vtkSmartPointer<vtkGPUVolumeRayCastMapper> volumeMapper2 =
		vtkSmartPointer<vtkGPUVolumeRayCastMapper>::New();
	volumeMapper2->SetInputData(reader->GetOutput());
	/****************************************************************/
	vtkSmartPointer<vtkVolumeProperty> volumeProperty1 =
		vtkSmartPointer<vtkVolumeProperty>::New();
	volumeProperty1->SetInterpolationTypeToLinear(); //设置线性插值
	volumeProperty1->ShadeOn();//开启阴影功能 
	volumeProperty1->SetAmbient(0.4);//设置环境温度系数
	volumeProperty1->SetDiffuse(0.6);//设置漫反射系数
	volumeProperty1->SetSpecular(0.2);//设置镜面反射系数

	vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity1 =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	compositeOpacity1->AddPoint(70, 0.0);
	compositeOpacity1->AddPoint(90, 0.4);
	compositeOpacity1->AddPoint(180, 0.6);
	volumeProperty1->SetScalarOpacity(compositeOpacity1);
	
	vtkSmartPointer<vtkVolumeProperty> volumeProperty2 =
		vtkSmartPointer<vtkVolumeProperty>::New();
	volumeProperty2->SetInterpolationTypeToLinear(); //设置线性插值
	volumeProperty2->ShadeOn();//开启阴影功能 
	volumeProperty2->SetAmbient(0.4);//设置环境温度系数
	volumeProperty2->SetDiffuse(0.6);//设置漫反射系数
	volumeProperty2->SetSpecular(0.2);//设置镜面反射系数

	vtkSmartPointer<vtkPiecewiseFunction> compositeOpacity2 =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	compositeOpacity2->AddPoint(100, 0.0);
	compositeOpacity2->AddPoint(140, 0.4);
	compositeOpacity2->AddPoint(180, 0.6);
	volumeProperty2->SetScalarOpacity(compositeOpacity2);
	/
	vtkSmartPointer<vtkPiecewiseFunction> gradientOpacity =
		vtkSmartPointer<vtkPiecewiseFunction>::New();
	gradientOpacity->AddPoint(10, 0.0);
	gradientOpacity->AddPoint(90, 0.5);
	gradientOpacity->AddPoint(100, 1.0);
	volumeProperty1->SetGradientOpacity(gradientOpacity);
	volumeProperty2->SetGradientOpacity(gradientOpacity);

	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);
	volumeProperty1->SetColor(color);
	volumeProperty2->SetColor(color);
	/****************************************************************/
	vtkSmartPointer<vtkVolume> volume1 =
		vtkSmartPointer<vtkVolume>::New();
	volume1->SetMapper(volumeMapper1);
	volume1->SetProperty(volumeProperty1);

	vtkSmartPointer<vtkVolume> volume2 =
		vtkSmartPointer<vtkVolume>::New();
	volume2->SetMapper(volumeMapper2);
	volume2->SetProperty(volumeProperty2);
	//
	double View1[4] = { 0, 0, 0.5, 1 };
	double View2[4] = { 0.5, 0, 1, 1 };
	vtkSmartPointer<vtkRenderer> render1 =
		vtkSmartPointer<vtkRenderer>::New();
	render1->AddVolume(volume1);
	render1->SetViewport(View1);
	render1->SetBackground(1, 1, 0);

	vtkSmartPointer<vtkRenderer> render2 =
		vtkSmartPointer<vtkRenderer>::New();
	render2->AddVolume(volume2);
	render2->SetViewport(View2);
	render2->SetBackground(0, 1, 0);

	vtkSmartPointer<vtkRenderWindow> rw =
		vtkSmartPointer<vtkRenderWindow>::New();
	rw->AddRenderer(render1);
	rw->AddRenderer(render2);
	rw->SetSize(640, 320);
	rw->SetWindowName("Differ Gray Opacity Function");

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

	render1->GetActiveCamera()->SetPosition(0, -1, 0);
	render1->GetActiveCamera()->SetFocalPoint(0, 0, 0);
	render1->GetActiveCamera()->SetViewUp(0, 0, 1);
	render1->GetActiveCamera()->Azimuth(30);
	render1->GetActiveCamera()->Elevation(30);
	render1->ResetCamera();
	render2->SetActiveCamera(render1->GetActiveCamera());

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