Some time ago, Han Feng of Hyperbody [hyperbody.nl / makeahybrid.org] did a really great job and modified the old 3d voronoi grasshopper definition and made it much more sleek and streamlined. In all good faith, here it is: http://improved.ro/blog/2011/06/gh-3d-voronoi-for-grasshopper-update/

I hope this solves more problems than it causes. Nevertheless, please take your time and read this or/and this article as an exercise in self-critique (especially the first one). Maybe you’ll change your final presentation discourse a bit.