[vtkusers] Mean Curvature

[Prathap Nair]

Hello,

I am using VTK 4.2 on Windows XP with VC++ 6.0 and am relatively new to VTK. I am doing a project where I have to register two 2.5 D scans (two surfaces) which are in wavefront obj format. I have had no problems so far in terms of rendering or implementation of the Iterative Closest Point Transform.

Now i need to implement a landmark detection algorithm that needs the values of Gaussian and Mean curvatures at each point of the surface. I have written the code using the VTK class vtkCurvatures and it compiles and runs error free. I am able to get values for Gaussian curvature, but for mean curvature i get the value zero at all points of the scan. Snippet of my code is provided below, if anyone has faced this problem before or knows what I am doing wrong, please please let me know.

Thanks in advance.

Regards,

Prathap Nair
Dept of Electronic Engineering,
Queen Mary, University of London,
Mile End Road, London E1 4NS (UK).

/************************Code Snippet***************/

//face 3 is a polydata object containing the surface
this->face3->DeepCopy(face2->GetOutput());


//Get the Mean curvature and store in vtkDoubleArray "mvals"
this->curvm->SetInput(this->face3);                    //curvm is an object of vtkCurvatures
this->curvm->SetCurvatureTypeToMean();
this->curvm->Update();
this->mvals->DeepCopy(curvm->GetOutput()->GetPointData()->GetScalars());

//Get the Gaussian curvature and store in vtkDoubleArray "gvals"
this->curvg->SetInput(this->face3);                    //curvg is an object of vtkCurvatures
this->curvg->SetCurvatureTypeToGaussian();
this->curvg->Update();
this->gvals->DeepCopy(curvg->GetOutput()->GetPointData()->GetScalars());
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