用于理解vtkPolyData和vtkCellArray的一段代码

#include "vtkActor.h"
#include "vtkCamera.h"
#include "vtkCellArray.h"
#include "vtkFloatArray.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkPolyDataMapper.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"

int main()
{
int i;
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}};
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.
vtkPolyData *cube = vtkPolyData::New();
vtkPoints *points = vtkPoints::New();
vtkCellArray *polys = vtkCellArray::New();
vtkFloatArray *scalars = vtkFloatArray::New();

// Load the point, cell, and data attributes.
for (i=0; i<8; i++) points->InsertPoint(i,x[i]);//将点保存在vtkPoints中
for (i=0; i<6; i++) polys->InsertNextCell(4,pts[i]);//6个面，每个面由4个点组成，对应pts[i]的4个ID
for (i=0; i<8; i++) scalars->InsertTuple1(i,i);//这个应该是为每个点赋颜色用的，对应 cubeMapper->SetScalarRange(0,7);

// We now assign the pieces to the vtkPolyData.
cube->SetPoints(points);
points->Delete();
cube->SetPolys(polys);
polys->Delete();
cube->GetPointData()->SetScalars(scalars);
scalars->Delete();

// Now we'll look at it.
vtkPolyDataMapper *cubeMapper = vtkPolyDataMapper::New();
cubeMapper->SetInput(cube);
cubeMapper->SetScalarRange(0,7);
vtkActor *cubeActor = vtkActor::New();
cubeActor->SetMapper(cubeMapper);

// The usual rendering stuff.
vtkCamera *camera = vtkCamera::New();
camera->SetPosition(1,1,1);
camera->SetFocalPoint(0,0,0);

vtkRenderer *renderer = vtkRenderer::New();
vtkRenderWindow *renWin = vtkRenderWindow::New();
renWin->AddRenderer(renderer);

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

renderer->AddActor(cubeActor);
renderer->SetActiveCamera(camera);
renderer->ResetCamera();
renderer->SetBackground(1,1,1);

renWin->SetSize(300,300);

// interact with data
renWin->Render();
iren->Start();

// Clean up

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

return 0;
}