EnigmA Amiga Run 1998 July/EnigmA AMIGA RUN 29 (1998)(G.R. Edizioni)(IT)[!][issue 1998-07 & 08].iso/recent/iib122.lha/IIB/Threads/Modelling_a_Boat

Internet Message Format | 1998-06-21 | 6KB

Date:         Wed, 17 Jun 1998 12:33:20 -0400
From:         "Tim Wilson [Crestline]" <[e-mail]>
Subject:      [IML] IFW: - Modeling

To Michael Murray re your message of Tue, 16 Jun 1998:

>>>
    Would any of you modeling wizards out there have any tips/tutorials
on modeling a boat hull? I tried doing an outline (looking from the top)
of half the hull, adding faces, copying, pasting and flipping the copy
and then joining the two before extruding. The problem with that is the
sides of the hull are  flat whereas a real boat hull of course is curved
from top to bottom as well as usually curving from front to back
>>>

   Date:         Thu, 18 Jun 1998 06:41:01 +0100
   From:         Matthew O'Neill <[e-mail]>
   Organization: Spectrum
   This is the best way to do it. Using the forms editor, you would only
   need 2 key slices to do it, one smaller than the other.

There are probably a number of different ways you can create a shape like
this. One would be skinning. Create the outline of your boat from overhead.
Then go to a front view and create sort of a U-shaped cross-section just
with edges (as a separate object). Go to the top view, and clone a number
of copies of the cross-section along the length of the boat at regular
intervals. Scale each one in X so it fits your original contour. Then pick
them in order and apply a skin.

You might want to change the shape of the cross-sections as well so they
start out V-shaped near the front and get more U-shaped toward the back. I
real boat probably has a sectional shape more like this->  {  (turned on
its side, and increased in depth). Studying the plans of a real boat might
help.

Another approach you could use is to create your cross-section, extrude it
with about 20 sections. Then in the top view scale each section (using Drag
Box in Pick Point mode), to match your contour.

If you want to add some curve from front to back as well, then go to the
side view and adjust the depth (scale in Z) of each cross-section as well.

I think Steve Worley did a tutorial on how to do something like this in the
Forms editor as well, in the old ``Understanding Imagine 2.0.''

A program with rail extrusion like Freeform, or 3DS's Lofter, or maybe
Rhino might provide still an easier way to do this as well.

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Date:         Thu, 18 Jun 1998 07:43:21 +1200
From:         Gary Dierking <[e-mail]>

This is close to the method that I've used and it has been the most
successful.
See the resulting canoe hulls at:
http://www.geocities.com/~garydierking/proas.html
Use the "add lines" tool to draw one half of the shape of the midships
section.  Extrude it to about 10 sections.  Use scaling and point
dragging to reshape the ends of the hull and to close up the bow.  It is
important to have an equal number of points in each section to end up
with a fair hull. After it all looks good use the "mirror" function to
add the other half of the hull.

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Date:         Wed, 17 Jun 1998 13:50:16 -0500
From:         Jeff Krase <[e-mail]>

I don't know if it was in "Understanding Imagine 2.0" or not, but it was =
in that compilation of web tutorials and textures that Impulse produced...
Can't remember the name of it for the life of me, but it's not version =
specific and it has bits from other "old timers" like Torgeir.  Ask Mike =
or Tor -- or better yet, do a search on the web for "Forms Editor" and =
"Worley."

Regarding Rhino, it might be as easy to do a boat hull if you were =
proficient, but the Forms editor and Worley's tutorial could produce =
faster results, most likely, even if you don't have previous experience =
with that portion of Imagine's modelling tools.

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Date:         Thu, 18 Jun 1998 15:16:12 -0400
From:         "Tim Wilson [Crestline]" <[e-mail]>

Dudes,

Building a boat hull in Imagine shouldn't be that tough. I only mentioned
the other progs. with rail extrusion because that's sort of the de facto
quick and dirty way to build boat hulls. (Rail extrusion isn't much good
for anything else, IMO.) <g>

However, to be frank, that's not the way I'd do it myself. If you want
something really accurate like this, Imagine's discrete point editing
should make it a breeze. If you study the plans of a real boat (or plane
for that matter), you should be able to reproduce the structure
polygonally, using almost the exact same construction techniques as a real
builder.

If you want a more accurate/direct approach than skinning and extrusion,
then just plot out the critical points for the ribs and spine (or whatever
the correct nautical terminology is :) and then just connect the dots to
add your polygons. This approach should give you the most accurate shape
anyway. It might take a bit more time and skill, but the end result would
probably be well worth it.

Fill to Edge might come in handy for this as well. There really are about
10 different ways you could go about constructing something this in
Imagine. You could take a sphere, turn it on its side, cut it in half, and
reshape each cross-section. That's a method I often use to quickly rough
things out.

Or you could buy Alias and use NURBS. :)

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Date:         Thu, 18 Jun 1998 16:55:22 -0400
From:         Jon Galley <[e-mail]>

If anyone doubts the validity of point manipulation as a modeling
technique, I would recommend that you visit Crestline's web page!  If I am
not mistaken, Tim's figures are all modeled this way.

http://ourworld.compuserve.com/homepages/crestline/iobhuman.htm

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