@Noors: I think I will give the lights a shot, actually. That setup looks pretty straightforard, as long as I don't have to deal with cast shadows. I admit I've been hesitant since I've never actually done any lighting in Max before and I'm on a deadline. Easy to get sucked into the lighting rabbit hole, so I'll probably…
Got it working now, many thanks for the tutorial. (I'd been misled by a different tutorial, which showed a script being used in a different way.) Pretty similar effect to the other technique I described above, but more straightforward. Now if only I could get it faceted...
There used to be a shader that did exactly this, but I think it's pretty outdated, and I can't find it anymore. But, I also remember a script that added the lights and setup everything in a square plane, so all you had to do was render a top view of your object, I'll try to find it.