How to get the principal curvatures of a given mesh?

Hi smart guys,

I have a problem of getting principal curvatures from a given mesh (of a shape).

1. I am trying to use 'patchcurvature' method from Matlab file exchange. However, the method always given the positive curvatures. I think it might be that the method considered the mesh as separate patches, and calculate the principal curvatures for each patch.

[~,~,Dir1,Dir2,PrincipalCurvature1,PrincipalCurvature1]=patchcurvature(meshFaceVertices);

2. I also tried to use another method from Matlab file exchange called 'surfature'; however, it calculates the principal curvatures of a 'surface' defined by three 2D arrays of points on the surface. I am not sure how to create a 'surface' with 2D point arrays from a existing mesh defined by vertices and faces. There are some methods convert surface to mesh but not the other way around...

Any ideas would be appreciated. Thanks so much and Happy New Year!!!

Best, Aaronne.