Aha!  Good answer.  Thank you.  The ah, whaddyacall-Trumbore (dang, I have to backtrack to look up the proper name you gave me) code was using a returned distance value in the collision loop, and I just assumed this would be the same.  I hadn't really thought it through in terms of what I (might) know about your process.  So I did the right thing, in simply doing abs() for the value.

I would just leave it and note the potential for a negative value (if not explain what it represents), particularly if it can be more useful somehow in its current form.  Hmm.  As both distance and direction, it could be added to the vertex position as with vector.project.  This is basically both arguments you'd use in project, pre-glommed together.  Right?  (Note to self: stop asking more questions.  There are already too many of them.)

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Cage can be an opinionated jerk who posts without thinking.  He apologizes for this.  He's honestly not trying to be a turkeyhead.

Cage had some freebies, compatible with Poser 11 and below.  His Python scripts were saved at archive.org, along with the rest of the Morphography site, where they were hosted.