I’m totally new to blender and trying to improve my modeling skills.
I’m trying to produce quad-based models, because I was told that’s the way of a true blender-samurai.
Now I’m modeling a rounded baseplate with some holes in it.
As starting point I’ve used an circle and the mirror modifier on X and Y.
Now I would like to round the corners a bit by using subsurf modifier. Somehow the modifier produces an (for me) unexpected result - the plate has kind of bumps (see image).
Might also want to add a continuous supporting edge loop near the outer edge. Fastest way to do that is to select the outer face loops around the rim and do an outset (alt+(shift+)RMB to select face loops, i to inset and o to switch to outset mode)
It still has edges inside. Those are mesh errors and give a impossible mesh. The vertices/edges don’t line up with the object origin that the mirror modifier uses by default, they’re off along X and Z, so it won’t merge vertices at those planes. Clipping option helps to move those edges along corresponding axes so that they do line up, they snap on the mirror plane.
Polygonal modeling is surface type modeling. You’re trying to describe a continuous outside surface with this and those extra edges are not part of it. Same with what the mirror modifier is for - in this case you’re using it to model 1/8 of it, while the mirror completes the surface. Just have to make sure it does that.