Hi Glenn, welcome to MoI and to the forum!

> So it's just a visualisation thing and i'm being to precise...
>
> Am i right?

Yup, you're right! In order for a surface to be displayed it has to be broken down into triangles. You can sometimes see evidence of this triangulation in the display, especially if you zoom in closely and it can also be fairly more pronounced on surfaces that are sort of wide and only shallowly curved.

That particular kind of thing is just a display artifact and does not indicate any actual problem with the surface. The real surface is actually smooth there and as you already discovered when you go to do an export you can choose a high mesh density at export time if you want a smoother result.

The real-time display is more oriented around doing things quickly, so that you don't have to wait any extra time to see your model when you've just made a change to it.

Curves though are drawn in a pretty different way - they are dynamically broken down to be smooth looking at the view's current zoom level so you won't see curves or edges with that kind of thing, only the shaded surface part.

So yes what you are showing there is totally normal and is just something to ignore. There are other kinds of artifacts that can actually indicate a problem, but they look different than that, more like stuff sort of "leaking" out beyond the boundary rather than looking like line segments inside of the edge.

When you have 2 surfaces joined together at a common edge, they will have a common triangulation at that juncture so it's harder to notice this particular side effect on joined areas as compared to open edges.

- Michael