I'm pretty new to blender, what brought me here is that I'm working gon a project in which we're looking for a simple way to measure 3d cuts of a body scan, in order to identify spine deformations in patients. Basically we 3d scan their torso, cut it in Blender and measure the angle of the largest diameter versus the x-axis. That's the idea, also we need to find the centroid of the elliptical-like shape that will result from the cut, therefore we could use the min-diameter crossing the max diameter to find it. Some people said I should try other software, they indicated QGIS and ImageJ but some said it can be done in Blender somehow. So here I am.
To determinate the level of deformation of the spine we need to obtain the angle between PAX and BSR. And also compare the distances between the centroids of both a cut in the height of the torso and a cut in the base of the spine, when you draw one on top of the other you'll see they are quite far apart because of scoliosis or whatever deformation happened.