cutting a hole in cube with subdivision surface modifier already applied I'm trying to cut a rectangular hole in my cube. You can download my source file on this link. The cube was tempered with subdivision modifier and the shading is smooth. This is what I got so far:



I used the left block and a boolean modifier to cut a hole. The problem is that I need my hole to be exactly the same shape as block-right angles are necessity. The Blender gives a warning that my boolean modifier is not the first one and that results may not be what I expect. So how do I cut a block hole out of the object with smooth surface? This really bugs me and I'm very thankful for your help.

EDIT: situation after smoothing inner part of cube with subdivision modifier and Smooth option from Shading panel:
First things first. Boolean is not a good choice in my opinion to receive simple shapes like that.

If I understand you right, you only want a cube which has rounden edges with a rectangular whole in the middle.

This is how I would do it.
First create a simple Cube.



Than subdivide it twice



Delete the inner faces



Now select "Bridge Edge Loop" under the "CTRL +E" Sub Menu



Last but not least, round your edges



Now you can still add a subdivision Modifier to make it even more smooth.



To keep the whole sharp, select all edges and increase the Mean Crease to 1.



Now select the faces you want to be sharp and click Faces -> Sharp under the "Shading"-Tab