Is there a way to model a realistic box?
Not a cube, a box. One with sides and a top/bottom that opens.
I was able to do it by extruding all faces of a cube except the top one, then creating faces for the cube-shaped corners, but turning subsurf on to give it a slight round to the edges makes things seem… creasy in all the wrong places.
have you tried edge-creasing? make a edge loop near the corner on each side then subsurf then edge-crease to keep the face straight until it reaches the corner?
or bevel?
I was convinced that I needed subdivision for a mesh to look like something not out of Wing Commander… but it seems to look fine when rendered after ‘set smooth’ is used.
Rounding corners can be a good way to get more realism out of your model, but for something as sharp and rigid as a box a slight bevel along the edges should be all you need. Just remember to pay careful attention to your materials and lighting.