Curvy hull design

thats nice… looks good…great

I do but I don’t, I have a couple of years with rhino and planing hulls now, but mostly of what I have done was with already existent 3D hulls, or the extreme opposite, creating from nothing (that is where Orca3D come in handy). But, to be really honest, mostly of what I have done is fixing naked edges, adding thickness and 3D printing 1:10 or 1:25 hull pieces and gluing then together (image attached).

I do wonder if manual methods would translate nicely into rhino (lines plan + french curves or table of offsets)

I do not have the experience to help much yet, my intend was to fire up the conversation so I can follow along as well, it seen like it worked because we already got a lot of tips and tricks to read :smiley:

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haha…thanks altamiro…thats nice 3d print hull.

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The traditional two dimensional “lines” based design methods using stations, waterlines, buttocks, diagonals, sheer, chine, keel/rabbet, etc can be quicker working in a good CAD system such as Rhino compared to drawing on paper with ships curves and splines. The challenge with that method, whether done on a computer or on paper, is ensuring the curves intersect or are at least “close enough”; not just that the individual curves are each fair on their own. The waterlines and buttocks need to intersect. The buttocks need to intersect with the sheer. The waterlines need to intersect with the stem and sheer. And so forth. This is tedious and very time consuming for a round bottom hull, even when done using Rhino or similar. For a simple hard chine hull with simple surfaces between the major curve sit is much simpler.

I have started with numerous sets of lines and tables of offset and created faired surfaces. My approach is to import the offsets as 3D points into Rhino, check and correct obvious errors, fair out any major discrepancies, and then move onto creating and fairing the surface. The number of control points of the surface can be less than and frequently much less than the total number of control points in the “lines” curves. Once the model is faired it is used to for analysis and to obtain a set of faired lines and offsets, CNC cutting files, etc.

Working with a surface rather than a set of lines is not new. Nathaniel Herreshoff, the American sailing yacht designer of the late 19th and early 20th century, created his hull shapes by carving a half model and ensuring the half model surface had the desired shape and was smooth. The half model was measured with high precision using a custom machine with the results recorded in a book of offsets. The offsets then went to the building floor.

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How to produce this transom design on hull?

is it possible do you think that one single span can make complete surface starting from fore to transom?
any command and procedure you think is possible to provide such aft transom?

from my side may be just need to sketches top & bottom curves,loft them,thats it,but i doubt such beautiful bending can be reason of something else?

I would create a surface across the stern which does not include the corner blends. This can probably be single span. Then I would work the corner blends. Several iterations of both the main surface and the blends will probably be needed.

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thanks,i guess yeah this should be the way

An example of a blended stern using the hull side example I provided above. This is a first pass and can be improved.
TransomEx20Oct21.3dm (2.9 MB)

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nice

Are either of these available for Mac?

hello davidcockey

would you let me know, how create this crease, firstly i am not sure whether is crease or something else(seperate surface welded to main hull surface).
Could you see?


I would model use separate surfaces above and below the crease.

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ok thanks

DevLoft is a native Rhino command, I think it was introduced in Rhino6

DevSrf plugin does not have a Mac option on Food4Rhino

I don’t know if Orca3D works with Mac but @bhays may help answering that.

Great discussion! The Orca3D plug-in is available only for Windows.

Whenever you have a meeting at an angle you are going to need separate surfaces.

Clearly, the beach club will have to be created as a separate assembly.

The bulge at the waterline probably should be a separate assembly.

If there is a meeting that is continuous, you can usually make them the same surface. In places where there is a sharp bulge, it is usually easier to have separate surfaces.

A surface or curve in Rhino can have a kink, also known as a crease in a surface. A kink/crease can be inserted into a surface or a curve using InsertKink. Surfaces with kinks/creases can also be created by some commands if input curves have kinks and if CreaseSplitting is not enabled.

Usually I avoid surfaces with kinks/creases in curves and surfaces because they can introduce complications in some instances. However I do use surfaces with creases when doing initial design work of hulls with faceted, sometimes called multi-chine hulls. In that situation it is convenient to be able to manipulate the shape of the crease while ensuring continuity of the surfaces.

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Thankyou vey much for this info Minao. Unfortunately, i am unable to make this hull, i tried and badly failed


The GA if i follow, it doesnot create correct design,this hull looks more tricky than i thought for.

mack, have you designed any hulls previously? Areas of this one are more difficult to make look right than initially apparent.

davidcockey, thankyou for all tips throughout this thread,i have tried catamaran and monohulls whch were i guess simple,but its first time guess i am introduced to such complexity of curvyness, i am not sure ,if you would like to see, i can share you the GA, but really if i trace GA blue print curves and also trying in later stage Control point manipulation, but after all this i was able to produce curvyness in hull, by nudging control points even aft part of hull was amost correct, but bow part which produced never matched real bow shape.