WIP - HSK Kormoran

 From:  JPBWEB
Hello Mark,

Well, like you, I did not like the hull I got, and I rebuilt it sooo many times. The rudder area is troublesome because it changes shapes so radically in a small area. This is probably a limitation of NURBS. It think it best to append a separate rudder area and blend it to the hull. This is a challenge of its own though because of continuity issues, hence the effort to generate a one-piece hull in the first place. MoI (like Rhino, to be fair) does not have the sort of continuity tools that high-end 3D design products offer. I have become less obsessed with continuity but there still needs to be a reasonably smooth connection between hull parts.

Another area of frustration was that there are a few parts of the hull that need to get depth (at the bow mostly). This should be an easy case of using the Shell command, but for some reason, those parts when given depth, will not merge with the body of the ship (using Boolean). I suppose it is because there are tiny areas that are empty spaces where the parts do not overlap. I have resorted to giving the entire hull the required depth and then build up the enclosed space that forms the biggest part of the hull.

On the hull generation matters, I would suggest the following guidelines that come from long and painful experience:

• Try to generate your hull in one go inasmuch as it does not interfere with making a hull with the correct shape.
• Do not fiddle with curves manually. Use blend (with “vanilla settings” i.e. bulge=1) as much as possible. Often, Tangency is more than good enough. Resort to G2 and G3 only in case of dire need.
• Only use as few stations as possible. More is definitely less
• Use as few different shapes of stations as possible. Much of a ship hull is a variation of the master frame. Often, transition between different shapes is best left to MoI. Sometimes, an intermediary station might be useful though.
• Remember that most plans are second or third hand information and might not be accurate at all. If a hull “looks” right and is smooth, nobody will be able to prove you wrong.
• Disregard plan lines for building the hull if you need to, but check your work by projecting verticals that should match the plan reasonably and give you a body plan that “feels” OK.
• If you need to, make some parts of the hull as a separate fixture, but use the best blend you can. MoI does not have analysis tools, but Rhino has pretty good ones.
• Render your hull frequently while in WiP. MoI surfaces often look wonderfully clean, but are not, and sometimes the engine shows kinks etc. that are not really there. Rendering is the best way to “see” for yourself.

I will post some WiP shots as soon as I get the chance.