VTK 实例16：手动创建vtkPolyData数据集

 

// This example shows how to manually create vtkPolyData.
#include "vtkAutoInit.h" 
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);

#include "vtkActor.h"
#include "vtkCamera.h"
#include "vtkCellArray.h"   //基元数组类
#include "vtkFloatArray.h"  //浮点型数组类
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"    //多边形数据类型类
#include "vtkPolyDataMapper.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"

int main()
{
  int i;
  //立方体的八个顶点（每个顶点坐标由三个点组成）
  static float x[8][3]={{0,0,0}, {1,0,0}, {1,1,0}, {0,1,0},
                        {0,0,1}, {1,0,1}, {1,1,1}, {0,1,1}};
  //立方体的六个面（每个面由四个点的标号组成）
  static vtkIdType pts[6][4]={{0,1,2,3}, {4,5,6,7}, {0,1,5,4},
                        {1,2,6,5}, {2,3,7,6}, {3,0,4,7}};
  
  // We'll create the building blocks of polydata including data attributes.
  //实例化一个多边形数据对象cube
  vtkPolyData *cube = vtkPolyData::New();
  //实例化一个点对象points
  vtkPoints *points = vtkPoints::New();
  //单元对象
  vtkCellArray *polys = vtkCellArray::New(); 
  //浮点数组对象
  vtkFloatArray *scalars = vtkFloatArray::New();

  // Load the point, cell, and data attributes.
  for (i=0; i<8; i++) points->InsertPoint(i,x[i]);//加载立方体的8个顶点
  for (i=0; i<6; i++) polys->InsertNextCell(4,pts[i]);//加载每个面由4个点组成的六个面
  for (i=0; i<8; i++) scalars->InsertTuple1(i,i);//绑定标量数据

  // We now assign the pieces to the vtkPolyData.
  //与vtkPolyData型数据对象进行关联
  cube->SetPoints(points);//进行点关联
  points->Delete();
  cube->SetPolys(polys);//进行面关联
  polys->Delete();
  cube->GetPointData()->SetScalars(scalars);//进行元组绑定
  scalars->Delete();

  // Now we'll look at it.
  //多边形数据送入图像界面进行绘制

  vtkPolyDataMapper *cubeMapper = vtkPolyDataMapper::New();
      cubeMapper->SetInputData(cube);//vtkPolyData数据输出给映射器输入
      cubeMapper->SetScalarRange(0,7);//设置标量数据范围0~7

  //实例化一个演员cubeActor
  vtkActor *cubeActor = vtkActor::New();
      cubeActor->SetMapper(cubeMapper);

  vtkCamera* camera = vtkCamera::New();
      camera->SetPosition(1, 1, 1);//设置相机位置为（1，1，1）
      camera->SetFocalPoint(0, 0, 0);

  vtkRenderer* renderer = vtkRenderer::New();
      renderer->AddActor(cubeActor);
      renderer->SetActiveCamera(camera);
      renderer->ResetCamera();
      renderer->SetBackground(1, 1, 1);
     
  vtkRenderWindow *renWin = vtkRenderWindow::New();
      renWin->AddRenderer(renderer);
      renWin->SetSize(300, 300);

  vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
      iren->SetRenderWindow(renWin);

  // interact with data
  renWin->Render();//绘制舞台上的东西
  iren->Start();//开始交互

  // Clean up
  cube->Delete();
  cubeMapper->Delete();
  cubeActor->Delete();
  camera->Delete();
  renderer->Delete();
  renWin->Delete();
  iren->Delete();

  return 0;
}