[vtkusers] Normals and curvatures of cloud points

[Ismail Elkhrachy]

Dear All,
I have a problem to calculate the normal vector and display it , and the 
curvature (Gaussian and mean) of my point cloud (xyz). My code is listed 
below, any one can help?
Many thanks,

The code is:
// This example demonstrate the use of VTK data arrays as attribute
// data as well as field data. It creates geometry (vtkPolyData) as
// well as attribute data explicitly.

// first include the required header files for the vtk classes we are using
#define     M_PI        3.141592653589793238
#include "vtkPointData.h"
#include "vtkVectorNorm.h"
#include "vtkCellData.h"
#include "vtkContourFilter.h"
#include "vtkTriangleFilter.h"
#include "vtkPolyDataToPolyDataFilter.h"
#include "vtkPolyDataNormals.h"
#include "vtkMatrix4x4.h"
#include "vtkMath.h"
#include "vtkActor.h"
#include "vtkDoubleArray.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkPolyDataMapper.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"
#include "vtkProperty.h"
#include "vtkLandmarkTransform.h"
#include "vtkTransformPolyDataFilter.h"
#include "vtkMaskPoints.h"
//#include "vtkNormals.h"

#include <iostream.h>
#include <iomanip>
#include <iostream>
#include <time.h>
#include <string>
#include <iostream>
#include <fstream>
#include <sstream>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include<fstream.h>

using namespace std;
int main()

{
   
    FILE *fp;
    FILE *fp2;
   
    std:: cout << "Program Starting" << endl;
   
    vtkPolyData* polyData1 = vtkPolyData::New();
    vtkPoints* cloud1      = vtkPoints::New();
   
   
    static float mypoint_1[3];
   
    //?????????????????????????????????????????????????????????????????ß
   
    fp=fopen("data\\scan4.nor","rb");
    if(fp==NULL)
    {
        puts("Cannot open firdt file");
        exit(0);
    }
    int PointNumberInScan1 = 0;
    while(fscanf (fp,"%f %f 
%f\n",&mypoint_1[0],&mypoint_1[1],&mypoint_1[2]) != EOF)
    {
        //   std::cout << mypoint_1[0] << ", " << mypoint_1[1] << ", " 
<< mypoint_1[2] << std::endl;
        cloud1->InsertNextPoint(mypoint_1);
        PointNumberInScan1 +=1;
    }
    fclose(fp);
   
    polyData1->SetPoints(cloud1);
   
    int num_of_points1 = polyData1->GetPoints()->GetNumberOfPoints();
    std::   cout << "in all, num of points in cloud 1 is " << 
num_of_points1 << endl;
   
   
   
    vtkPolyData* polyData2 = vtkPolyData::New();
   
   
    vtkPoints* cloud2      = vtkPoints::New();
   
   
    static float mypoint_2[3];
   
    fp2=fopen("data\\scan3.nor","rb");
    if(fp2==NULL)
    {
        puts("Cannot open scan 2 file");
        exit(0);
    }
    int PointNumberInScan2 = 0;
    while(fscanf (fp2,"%f %f 
%f\n",&mypoint_2[0],&mypoint_2[1],&mypoint_2[2]) != EOF)
    {
        // std::cout << mypoint_2[0] << ", " << mypoint_2[1] << ", " << 
mypoint_2[2] << std::endl;
        cloud2->InsertNextPoint(mypoint_2);
        PointNumberInScan2 +=1;
    }
   
    fclose(fp2);
   
    int numPoints =0;
    if (PointNumberInScan2 > PointNumberInScan2){
        numPoints = PointNumberInScan2;
    }
    else {
        numPoints = PointNumberInScan1;
    }
   
   
    polyData2->SetPoints(cloud2);
   
    int num_of_points2 = polyData2->GetPoints()->GetNumberOfPoints();
    std::   cout << "in all, num of points in cloud 2 is " << 
num_of_points2 << endl;
   
    //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
    vtkTriangleFilter *triangle1 = vtkTriangleFilter::New();
    triangle1->SetInput(polyData1); 
   
   
   
   
    vtkPolyDataNormals *Normals1 = vtkPolyDataNormals::New  ();
    Normals1->SetInput(triangle1->GetOutput());
    Normals1->SetFeatureAngle(60);
    Normals1->FlipNormalsOff();
    Normals1->Update();
   
  
  
   
   
   
     for (int pointID=0; pointID < 
Normals1->GetOutput()->GetNumberOfPoints();
    pointID++) {
    float *point =
    
(float*)triangle1->GetOutput()->GetPointData()->GetNormals()->GetTuple(pointID);
   
      printf("x-> %f",(float)point[0]);
      printf("y-> %f",(float)point[1]);
      printf("z-> %f",(float)point[2]);
   }
   
   
   
   
   
    vtkPolyDataMapper *Normals1Mapper = vtkPolyDataMapper::New();
    Normals1Mapper->SetInput(Normals1->GetOutput());;
    Normals1Mapper->ScalarVisibilityOn();
    Normals1Mapper->SetScalarRange (1, 1150); //((gradient->
    //   Normals1Mapper->GetOutput())->GetScalarRange());
   
    //    Create actor.
    vtkActor *Normals1Actor = vtkActor::New();
    Normals1Actor->SetMapper(Normals1Mapper);
    Normals1Actor->GetProperty()->SetColor(1,0.49,0.25);
   
   
    //    Create the rendering objects and render window.
    vtkRenderer* ren = vtkRenderer::New();
    vtkRenderWindow* renWin = vtkRenderWindow::New();
    renWin->SetPosition(512,0);
    renWin->AddRenderer(ren);
   
    // an interactor
    vtkRenderWindowInteractor* iren = vtkRenderWindowInteractor::New();   
    iren->SetRenderWindow(renWin); 
   
   
    // add the actor to the scene
   
    ren->SetBackground(1,1,0); // Background color white
    ren->AddActor(Normals1Actor);
   
    iren->Initialize();
    iren->Start();  
   
    Normals1Actor->Delete();
    ren->Delete();
    renWin->Delete();
    iren->Delete();
   
    return 0;
   }

-- 
M.Sc. Ismail Elkhrachy

Institut für Geodäsie und Photogrammetrie
Technische Universität Braunschweig
Gaußstr. 22   
38106 Braunschweig 
Germany
Mob.           : 0049 0163 3623486
Tel.           : 0049 0531 3917497
Fax            : 0049 0531 3917499
E-mail         : I.Elkhrachy at tu-bs.de, I.Elkhrachy at yahoo.com