Hi Elrick, yes probably Andrei's lofting method is what you'd want to look into.

But the whole area of "reverse engineering" where you're trying to reconstruct an existing shape accurately has a lot of complexity around it and it's not an area of work that MoI is really specifically focused on. So just keep in mind that it's a pretty advanced and tricky type of work that you're getting into here.

You'll generally want to make one single loft to be a broad and smoothly shaped surface, the other details like the sharp ridges and indentations will probably need to be trimmed out areas in the main hull where you have other smaller surfaces coming up from those trimmed areas, rather than trying to directly include those into one single loft.

> But by the looks of it only the most advanced and expensive mesh software can convert an Stl to an
> Iges accurately. GMD have a command to convert a polygon mesh to a solid (Iges) but the detail of
> the sharper edges are lost in the conversion.

Yes, polygon mesh data and CAD solids data are pretty different in structure. You can convert from CAD solids into meshes in a fairly straightforward way by dicing big smooth surface patches up into little facets but it's a quite complex process to go the reverse way and try to reconstruct large smooth surface patches from a big soup of little facet pieces.

There are various reverse engineering tools that are focused on that kind of stuff but they tend to be expensive and used for more special situations, not really part of the sort of "standard" CAD modeling toolset.

- Michael