If you were familiar with those formats, you would guess the answer.
STL is just a set of triangles (coded by their 3 vertices) while IGES normally stores exact geometry (NURBS, conics, etc). So, straightforward conversion is impossible (I don't mean translating each triangle as a separate surface what is basically useless).
If you know some semantics around STL vertices (e.g. a cloud of points belonging to a single surface) then you could try to reverse-engineer first (i.e. reconstructing surfaces) and then converting to IGES. Both steps are possible with Open CASCADE.
Hope this helps.
Commenter-1
02Commenter-2
Hello, Roman!
What tools from Open CASCADE could you recommend to reconstruct surface from point cloud? Do you mean "Surfaces from Scattered Points" component or something else?
Thanks.
03Commenter-1
Hello Oleg,
For commercial users I would suggest favoring "Surfaces from Scattered Points" indeed (within Value-Added software section). It justifies its price (very reasonable, imho) in terms of speed and quality gain.
For freebies the *Plate* packages (see OCC distribution) can perhaps be acceptable. IIRC, the Plate sample has some reconstruction use case.
Of course, other techniques such as GeomAPI_PointsToBSplineSurface, GeomFill, etc can suit for particular cases (e.g. the former - for grid of points).
