I tried to make a jewelery box by double extruding a cube's inside, then added a few divisions and wanted to render a smooth preview. The corners don't look so smooth, and the render time takes ages, even though the structure is not the most complex object in the scene.
It has low reflection too.
Smoothing it doesn't work either, it still has sharp areas near the corners.
How can I make a smooth-cornered box?
