Improvements of volume computation from nonparallel cross-sections

We describe an algorithm for volume evaluation of a 3D object from area measurements done in non-parallel cross-sections. The algorithm is based on Watanabe formula for volume computation and uses an interpolation by cubic splines. The same splines are applied also for computation of object area and centroid in every cross-section. It allowed us to derive an explicit formula for volume computation and to extend the algorithm described in GM Treece, et al. (1999).