"Ed Jackson" wrote in message
7.136...
I have a table of offsets for a hull design I would like to build. Does
anyone know of any softawre that I can use to plot these with? No big deal
if I have to do it by hand, but thought software might be interesting.

You can do it with any cad program. Just enter the points of offset for
every station on a different z-plane, spaced apart by the amount stated in
the offset table or building description. Most cad programs offer a single
point entity, which can often be set to appear as a little cross. Then, as a
simulation of a batten used on a real lofting floor, you can use a spline or
bezier curve to try to fit a smooth line between the points of a single
station. I found splines to be the easiest. After a while you get the right
feeling for the number of control points to start with. Mostly you can do it
with tree control points for a round-bilge design, but in keel or transom
areas you might need 4 or even 5.

After you entered the curves for every station, you'll have a nice 3d wire
model of your boat. Then rotate it and start drawing the buttock points and
draw their splines. Then you'll often notice that in order to the the
buttocks smooth, you'll have to modify the station curves again. Kind of an
iterative process. And at last, you can do the same procedure for the
diagonals as well.

Meindert

It is possible to loft and fair a hull in Rhino, starting with a table
of offsets but it is tedious.
I love Rhino and use it everyday but for a job like this one, I would
use Prolines. I still have an old version (6) and it has great fairing
tools:
http://www.vacantisw.com/
You can enter the offsets directly in Porlines, one station at a time
and
Prolines will create a surface between your offsets but not
necessarilly on those points. It will detect unfair points.

Whatever the CAD tool lofting and fairing will always be more accurate
on the computer than on the floor. I did it the old fashioned way for
years but the surface analysis tools in CAD are much better than the
naked eye.


Jacques from bateau.com