alphaShape, problems to define surface of 3D figure

Hello all,

I have a matrix with the coordinates of a 3D surface. (scattered image of points and surface on Paraview are attached).

I want to use alphaShape (or any other module) to extract the information of volume and area of the surface. I have modified the alphaShape value and when it is to big the points connecting the edges of the leading tip are linked to the points at the other side and when it is small, not all the points are represented (see attached figure)

the code that I have used is also attached.

Any idea about what I could do?