I also would be very interested to see replies to this question.
I do suspect that watching an experienced boatbuilder do this is
probably the only way to learn, and it's an art as much as a skill.
I have seen it done once, and not done ideally at that.

Just to keep this thread alive for a while, until I finish building a
computer model of recreational rowing shell I built recently. The idea was
to use "trilateration" - a technique used by GPS. Basically it involves
measuring distances of certain points on a hull from three different
referent points. It is then possible to calculate xyz coordinates of those
measured points on the hull. My boat is a single-chine ply hull, so I just
measured keel, chine and sheer. Waterlines and stations will be created in
SW later. I'll keep you posted.