Laplacian Filter

Support
1

Hi, I want to use a smoothing tool for my poly data.

my poly data is a surface mesh of grey matter.

However, when I use a smoothing filter, the surfaces intersect each other.

            int smoothingIterations = 40;
            double passBand = 0.001;
            double featureAngle = 90.0;
            vtkWindowedSincPolyDataFilter smoother = vtkWindowedSincPolyDataFilter.New();
            smoother.SetInputConnection(surface.GetOutputPort());
            smoother.SetNumberOfIterations(smoothingIterations);
            smoother.BoundarySmoothingOff();
            smoother.FeatureEdgeSmoothingOff();
            smoother.NonManifoldSmoothingOff();
            smoother.NormalizeCoordinatesOff();
            smoother.SetFeatureAngle(featureAngle);
            smoother.SetPassBand(passBand);
            smoother.Update();

this is my sample code.
How can I smooth complicated surface mesh such as GM, WM without any line intersection, triangle intersection?
If any suggestions, it would be so great

Thanks.

2

The smoothing filters in VTK are topological operations, they do not check for geometric intersection. You’ll have to write your own filter for that - it’s a very complex algorithm.

1 Like
3

Is there any paper or related algorithm for that?
I read your triangulation algorithm paper(including decimation).
I think you have the solution for the smoothing problem.

4

One simple solution is to perform smoothing before surface extraction, because no self-intersection may occur in labelmaps.

However, most likely a simple generic surface smoothing will not get you too far. For proper analysis you will probably have to implement a surface generation pipeline that is similar to FreeSurfer.