Thanks for the response. I am not exactly sure what the outputs would be. In Fusion software, voxels are created and stored in many "height-slice" DTM's and also within a singular descriptive CSV describing, I believe, statistics on elevational statistics of returns within each voxel (see grimetrics or cloudmetrics;
http://forsys.cfr.washington.edu/software/fusion/FUSION_manual.pdf). Having metrics on the relationships between points within the voxels versus between points and the ground, would be of great use in the world of machine learning, and likely other applications.
Does this get at your question?
Thanks again