MUMOK is a hermetic, nearly windowless building that is anything but open and airy. It takes a master like Gerwald Rockenschaub to give this bunker a sense of weightlessness and openness—and that despite the show’s notoriously difficult format, the retrospective. Turned off, perhaps, by the prospect of yet another anxious heaping up of work, Rockenschaub rose above the usual demand for overflowing halls with a self-assured display of nearly empty space. With the precision of a marksman (and just twelve works), he hit the bull’s-eye.

“4296 m3” is a cryptic title with a simple explanation: It refers