VTK学习笔记-1

对于TIFF图像的读取时候，TIFF reader所读取和存储的是点格式，即point data in the "Tiff Scalars" array name; 对于体素需要转化为cell data。对于volume image的可视化 in a sort of parametric dimensions (namely pixel width, pixel height, number of tiff images).。使用 transform filters to scale to physical dimensions.
以下是使用VTK进行可视化的一个例子：

#include <vtkSmartPointer.h>
#include <vtkImageViewer2.h>
#include <vtkTIFFReader.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include<vtkImageStack.h>
#include<vtkImageReader.h>
#include<vtkImageMapper3D.h>
#include<vtkImageData.h>
#include<vtkVolumeProperty.h>
#include<vtkStructuredPointsReader.h>
#include<vtkPiecewiseFunction.h>
#include<vtkColorTransferFunction.h>
#include<vtkVolumeRayCastCompositeFunction.h>
#include<vtkVolumeRayCastMapper.h>
int main()
{
vtkTIFFReader *reader =vtkTIFFReader::New();
vtkImageData *image =vtkImageData::New();
reader->SetFilePrefix ("E:\\VTK_examples\\testdata\\" );
reader->SetDataExtent(0,2062,0,1490,0,13);
reader->SetFilePattern("%s%01d.tif");
reader->Update();
//image=reader->GetOutput();
/* int dims[3];
reader->GetOutput()->GetDimensions(dims);
std::cout<<"图像维数:"<<dims[0]<<" "<<dims[1]<<" "<<dims[2]<<std::endl;

double origin[3];
reader->GetOutput()->GetOrigin(origin);*/
//std::cout<<"图像原点:"<<origin[0]<<" "<<origin[1]<<" "<<origin[2]<<std::endl;
//double spaceing[3];
//reader->GetOutput()->GetSpacing(spaceing);
//std::cout<<"像素间隔:"<<spaceing[0]<<" "<<spaceing[1]<<" "<<spaceing[2]<<std::endl;
//int* dim_s = image->GetDimensions();
// // int dims[3]; // can't do this
//
// std::cout << "维数: " << " x: " << dim_s[0] << " y: " << dim_s[1] << " z: " << dim_s[2] << std::endl;
// std::cout << "Number of points: " << image->GetNumberOfPoints() << std::endl;//所有像素点的个数
// std::cout << "Number of cells: " << image->GetNumberOfCells() << std::endl;//Standard vtkDataSet API methods.
//image->CopyStructure(reader->GetOutput());
//stack->AddImage(reader)
/* reader->Update();
image->Update();*/
//3D的显示
// 创建标准的渲染器与映射器。
vtkRenderer *ren1=vtkRenderer::New();
vtkRenderWindow *renWin=vtkRenderWindow::New();
renWin->AddRenderer(ren1);
vtkRenderWindowInteractor *iren=vtkRenderWindowInteractor::New();
iren->SetRenderWindow(renWin);
// 创建标量到不透明度的转移函数。
vtkPiecewiseFunction *opacityTransferFunction=vtkPiecewiseFunction::New();
opacityTransferFunction->AddPoint( 0.0, 0.0);
opacityTransferFunction->AddPoint(255, 1.8);

// 创建标量的颜色的转移函数。
vtkColorTransferFunction *colorTransferFunction=vtkColorTransferFunction::New();
/* colorTransferFunction->AddRGBPoint(  0.0, 0.0, 0.0, 0.0);
colorTransferFunction->AddRGBPoint( 128.0, 1.0, 0.0, 0.0);*/
colorTransferFunction->AddRGBPoint(128.0, 0.0, 0.0, 1.0);
colorTransferFunction->AddRGBPoint(192.0, 0.0, 1.0, 0.0);
colorTransferFunction->AddRGBPoint(255.0, 0.0, 0.2, 0.0);

// 设置属性，其中包括两个映射函数。
vtkVolumeProperty *volumeProperty=vtkVolumeProperty::New();
volumeProperty->SetColor(colorTransferFunction);
volumeProperty->SetScalarOpacity(opacityTransferFunction);
volumeProperty->ShadeOn();
volumeProperty->SetInterpolationTypeToLinear();

// 光线投射映射器知道如何渲染数据。
vtkVolumeRayCastCompositeFunction  *compositeFunction=
vtkVolumeRayCastCompositeFunction::New();
vtkVolumeRayCastMapper *volumeMapper=vtkVolumeRayCastMapper::New();
volumeMapper->SetVolumeRayCastFunction(compositeFunction);
volumeMapper->SetInputConnection(reader->GetOutputPort());

// vtkVolume掌管映射器和属性对象，可控制体数据的位置和朝向
vtkVolume *volume=vtkVolume::New();
volume->SetMapper(volumeMapper);
volume->SetProperty(volumeProperty);

ren1->AddVolume(volume);
ren1->SetBackground(1, 1, 1);
renWin->SetSize(600, 600);
renWin->Render();

iren->Initialize();
iren->Start();

return 0;

}