VTK体绘制基础

以下代码为VTK体绘制，一个简单的例子，方便初学者迅速入门。

  1
  2vtkRenderer *aRender = vtkRenderer::New();     //设置绘制类
  3vtkRenderWindow *renWin=vtkRenderWindow::New();//设置绘制窗口
  4renWin->AddRenderer(aRender); //装载绘制类
  5vtkRenderWindowInteractor *iRen=vtkRenderWindowInteractor::New();//设置绘制窗口的交互
  6iRen->SetRenderWindow(renWin); //装载绘制窗口
  7
  8//读取数据
  9vtkVolume16Reader *reader=vtkVolume16Reader::New();
 10reader->SetDataDimensions (64,64);//设置图像像素值
 11reader->SetImageRange (1,93); //设置图片数量
 12reader->SetDataByteOrderToLittleEndian();
 13reader->SetFilePrefix("E://实验//headsq//quarter");//设置数据路径
 14reader->SetDataSpacing (3.2,3.2,1.5); //设置数据的间距
 15
 16
 17//对读取数据类型匹配
 18vtkImageCast *readerImageCast = vtkImageCast::New();
 19readerImageCast->SetInput((vtkDataObject *)reader->GetOutput());
 20readerImageCast->SetOutputScalarTypeToUnsignedShort();
 21
 22
 23//设置不透明度传递函数
 24vtkPiecewiseFunction *opacityTransferFunction=vtkPiecewiseFunction::New();
 25       opacityTransferFunction->AddPoint(70.0, 0.0);
 26    opacityTransferFunction->AddPoint(599.0, 0);
 27    opacityTransferFunction->AddPoint(600.0, 0);
 28    opacityTransferFunction->AddPoint(1195.0, 0);
 29    opacityTransferFunction->AddPoint(1200, .2);
 30    opacityTransferFunction->AddPoint(1300, .3);
 31    opacityTransferFunction->AddPoint(2000, .3);
 32    opacityTransferFunction->AddPoint(4095.0, 1.0);
 33
 34
 35
 36//设置颜色传递函数
 37vtkColorTransferFunction *colorTransferFunction = vtkColorTransferFunction::New();
 38      colorTransferFunction->AddRGBPoint(0.0, 0.5, 0.0, 0.0);
 39      colorTransferFunction->AddRGBPoint(500.0, 0.6, 0.5, 0.6);//皮肤
 40      colorTransferFunction->AddRGBPoint(1150, 1, 1, 0.96);//骨骼
 41      colorTransferFunction->AddRGBPoint(2550.0, 1, 1, 1);
 42
 43
 44//设置梯度传递函数
 45vtkPiecewiseFunction *gradientTransferFunction = vtkPiecewiseFunction::New();
 46gradientTransferFunction->AddPoint(0, 2.0);
 47gradientTransferFunction->AddPoint(50, 2.0);
 48gradientTransferFunction->AddPoint(200, 1.7);
 49gradientTransferFunction->AddPoint(300, 1.5);
 50gradientTransferFunction->AddPoint(500, 1.3);
 51gradientTransferFunction-> AddSegment (600, 0.73, 900, 0.9);
 52gradientTransferFunction->AddPoint(1150, 0.6);
 53gradientTransferFunction->AddPoint(1300, 0.1);  
 54
 55
 56
 57//定义并设置相关体属性
 58vtkVolumeProperty*volumeProperty=vtkVolumeProperty::New();
 59volumeProperty->SetColor(colorTransferFunction);
 60volumeProperty->SetScalarOpacity(opacityTransferFunction);
 61volumeProperty->SetGradientOpacity(gradientTransferFunction);
 62volumeProperty->ShadeOn();
 63volumeProperty->SetInterpolationTypeToLinear();
 64volumeProperty->SetAmbient(0.2);
 65volumeProperty->SetDiffuse(0.9);
 66volumeProperty->SetSpecular(0.2);
 67volumeProperty->SetSpecularPower(10);    
 68
 69
 70//定义光线投射方法为MIP体绘制方法,MIP为体绘制经典算法，还有合成体绘制等，只需要在这里重新定义既是
 71vtkVolumeRayCastMIPFunction*mipRaycastFunction = vtkVolumeRayCastMIPFunction::New();
 72
 73mipRaycastFunction->SetMaximizeMethodToOpacity();
 74
 75
 76//定义绘制者
 77vtkVolumeRayCastMapper *volumeMapper = vtkVolumeRayCastMapper::New();
 78volumeMapper->SetVolumeRayCastFunction(mipRaycastFunction);//载入体绘制方法
 79volumeMapper->SetInput(reader->GetOutput());
 80
 81
 82//定义Volume
 83vtkVolume *volume = vtkVolume::New();
 84volume->SetMapper(volumeMapper);
 85 volume->SetProperty(volumeProperty);//设置体属性
 86
 87
 88 // create a camera with the correct view up
 89  vtkCamera *aCamera = vtkCamera::New();
 90    aCamera->SetViewUp (0, 0, -1);
 91    aCamera->SetPosition (0, 1, 0);
 92    aCamera->SetFocalPoint (0, 0, 0);
 93
 94  aRender->AddVolume(volume);
 95  aRender->SetActiveCamera(aCamera);
 96  aRender->ResetCamera();
 97  aCamera->Dolly(1.5);
 98  aRender->SetBackground(0,0,0);
 99  aRender->ResetCameraClippingRange();
100 
101//aRender->AddVolume(volume); //将Volume装载到绘制类中
102//aRender->SetBackground(0, 0, 0);
103renWin->SetSize(500, 500);   //设置背景颜色和绘制窗口大小
104renWin->Render(); //窗口进行绘制
105
106
107iRen->Initialize();  
108iRen->Start(); //初始化并进行交互绘制
109reader->Delete();
110iRen->Delete();
111return 0;