[vtkusers] surface normal and curvatures calculation

[Ismail Elkhrachy]

dear All,
I have point cloud xyz coordinates of surface i want to claculate 
surface normal and curvatures (Min and Max).
I use visual c++6 with vtk 5.0. I am beginner with c++ op.  I used the 
following code,  i have got a stack!!

Theres is any one help thanks in advanced

ismail

#include "vtkPolyDataNormals.h"
#include "vtkCurvatures.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkPolyDataMapper.h"
#include "vtkRenderWindow.h"
int main()
{  
    FILE *fp;
      vtkPoints* cloud1      = vtkPoints::New();
        static float mypoint_1[3];
    fp=fopen("data\\scan4.nor","rb"); // cloud points X Y Z coordinates
    if(fp==NULL)
    {
        puts("Cannot open file");
        exit(0);
    }
    while(fscanf (fp,"%f %f 
%f\n",&mypoint_1[0],&mypoint_1[1],&mypoint_1[2]) != EOF)
    {
        cloud1->InsertNextPoint(mypoint_1);
    }
    fclose(fp);
     vtkPolyData* polyData1 = vtkPolyData::New();
    polyData1->SetPoints(cloud1);
    polyData1->GetPolys();  
        //Surface Normals calculation for polyData1
        vtkPolyDataNormals *Normals1 = vtkPolyDataNormals::New();
    Normals1->SetInput(polyData1);
    Normals1->SetFeatureAngle(45);
    Normals1->FlipNormalsOff();
    Normals1->Update();
        //I need to calculate Mean and Gauss curvatures But I am not 
sure with the following code or not
    vtkCurvatures *curvater = vtkCurvatures::New();
    curvater->SetInput(polyData1);
        // How to print the normal values and the curvature (Min and 
Max) foe each vertix
        for ( int pointID=0; pointID < polyData1->GetNumberOfPoints(); 
pointID++)
    {
     float *point =  
(float*)polyData1->GetPointData()->GetNormals()->GetTuple(pointID);
        printf("x-> %f",(*point+0) );
        printf("y-> %f",(*point+1) );
        printf("z-> %f",(*point+2) );
    }
        return 0;
}

-- 
M.Sc. Ismail Elkhrachy
PhD student

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