Howdi.

I promised to get back to the ship hull making issue, which is the only real problem area when modelling ships with NURBS. All the rest is fairly straightforward n-gonal shapes that can be made from basic NURBS techniques, but ship hulls are semi-organic and can be rather hard to get right. Of particular concern (at least to me) is continuity.

Here is one way I found to generate near-perfect smooth hulls from simple curves. This is a generic, somewhat WW2 Italian looking, cruiser hull, but the principle can apply to many other shapes. The model is made of three ovals that are waterlines: the keel, about flotation level and top. The sheer can be made by trimming later. All the rest are half stations, including stem and stern, at reasonably regular intervals. It is important to keep the curves as simple and clean as possible.

With this setup, one can generate a lovely hull in one go of the Network command. Et voilà!


Then, one can trim the top above the sheer line, rebuild the keel around the rudder and propellers, as the hull here is not smooth and continuous but displays hard angles etc.

I include the model. Feel free to experiment. I have a slight concern about the accuracy of the shapes and even the symmetry, but all in all it does not look too bad, I’d say.