you have resumed a very old discussion
Please, have a look at this document:
https://docs.otoy.com/Cinema4DH/C4DPlug ... -depth.htm
at this video:
https://vimeo.com/201203670
and at this discussion:
viewtopic.php?f=30&t=54023&hilit=depth+meter#p287060
If not enough, please, let us know.
ciao beppe