Odd creases on cylinder

Creating a carrot, I extruded a circle, scaled and move a bit.
The off thing is that if set to smooth I get two creases along two neighboring edge loops in the length of the cylinder.

Does anyone have any idea where it comes from? I checked for dupli verts and there are none.
Here is the blend file.


carrot.blend (553 KB)

It’s because there are inverted normals, to fix just select the model in edit mode and press CTRL+N (or Mesh -> Normals -> Recalculate Outside)

Thanks, that did the trick. What I do not understand is how this came about, as I started from a circle and extruded it to create the faces.

Most of the time, when this inverted face problem occurs it’s when i am in edit mode, working on 2 separate zones, then i make a face that is joining them.
No idea why this is happening too, fortunately nothing that a CTRL+N can’t fix

Its safe to say that if you start with a 2D object(planes or circles) and turn them into a 3D object you will have normals problems later.

If you wish to make a cylinder then start with a cylinder and you will avoid problems like this.

Well, I wouldn’t call an issue being fixed by a key combination a problem :wink:

I will try keeping your suggestions in mind. Thanks.