Trying to create a bed pillow-top, or quilted-top mesh. I'm just beating my head against the wall on this one. It's so close, but for some reason i just can't get it to work. Essentially, I modeled the pieces of it just fine, but when trying to add a subsurface, or subdivide the faces, or loop cuts to get it to smooth out, it just goes nuts.
I need to maybe subdivide just the mesh parts around the diamond shapes? And perhaps subdivide just the diamonds to be able to round out those shapes. Ideally it would look like the photo, where the hard stitching outline around the diamond shapes defines the depression in the fabric.
Here I am using a plane and could add the thickness to the bottom later, unless there is a much better way to do this.
and here how it is currently rendering; very blocky.
any help would be greatly appreciated!
here is the blend file






