VTK点云数据读取

//用VTK读取三维点云图并显示的程序遇到问题，求帮助
//该程序是读取txt里的三维点云数据然后显示出来
//程序如下：

#include "vtkRenderer.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkPoints.h"
#include "vtkUnsignedCharArray.h"
#include "vtkCamera.h"
#include "vtkPolyVertex.h"
#include "vtkUnstructuredGrid.h"
#include "vtkDataSetMapper.h"
#include "vtkCellLinks.h"
#include "vector"
#include "cstdlib"
#include "stdlib.h"
//#include "stdafx.h"
#include "string"   
#include "string.h"
#include "vtkPolyDataMapper.h"
#include "vtkActor.h"
#include "vtkProperty.h"
#include "iostream"
#include "fstream"

using namespace std;

int main()
{