I've done something similar, but what I've essentially done is build a pop-together screen hung with cheap mosquito netting that is sold in bulk off the roll. From slightly above head level to several folds draped on the ground - brass doesn't even roll away.
I found it mostly a minor annoyance picking up brass, but after many years in the army I was used to it. Once I got the Dan Wesson Commander Classic Bobtail in 10mm however, things moved to another level. When 10mm guys say their pistols really launch brass, they aren't kidding. The brass heads for the next postal zone. That's when I started thinking of how to stop brass missile launches without attaching something to the firearm, my arm, the bench, etc. This may not work at busy ranges that are kind of production line in how they run. My range it is pretty common to maybe only have one or two other guys there, and our setup has multiple 50 yard shooting bays separated by berms available to pistol shooters. So generally, on a range without lots of users, popping together a catcher screen is not a big deal and doesn't get in anybody else's way.
Our range keeps the ground covered in wood chips. The brass stays relatively clean and more importantly is easy to spot for pickup. The wire basket brass rollers work pretty good for speedy cleanup