The line (edge) on attached photo confuses me. It appears when extruding curved 2D figures. Why is it there?

While working on the model, I sometimes want to remove this line to get a cleaner view. I can remove it by making edges invisible, but then all other edges vanish, too - And in the settings I have so far not been able to remove it.

Better, I can select and name it as an object. When this line-object is made invisible, all the other edges are still there, and that is what I want. Only, does this affect anything when later sending the file to a 3D printer?

best
Claus

Hi Claus, an edge like that is normal to have with a closed surface, it's called the "seam edge" of the surface. It's just part of how NURBS surface geometry works. A NURBS surface is internally structured as a 4 sided patch. To form a closed surface like a cylinder out of a 4 sided thing, you need to roll it up so that opposite sides are touching each other. That spot where the opposite sides meet is that seam edge. A NURBS sphere made from one surface is similar, it also has a seam edge but additionally has the top and bottom edges pinched down to a single point.

It's just something to get used to I guess, it's normal to have it on a closed surface and it won't have any negative effect on 3D printing.

- Michael

<< and it won't have any negative effect on 3D printing.

... or 3D rendering! ;)

Got it, thanks!

best
Claus