THE MORE ONE LOOKS at the deviously serene, austere works of Dorothea Rockburne, the more baroque and optically destabilizing they become. Locus, 1972, features six unframed sheets of white paper, marked by sharp orthogonal creases, which here hang across two of the gallery’s white walls. At various points, their monochromatic yet multiplanar surfaces appear to project into relief and recede into depth, throwing into doubt whether the eye is perceiving actual volumes in space or a restrained trompe l’oeil illusion. Made of folded paper run through a printing press, the Locus suite numbers among