Shimaya describes the perceptual decomposition of 2D simple line drawings that might appear, in context, to have 3D volumetric interpretations. The approach taken is to complete line elements, look for connectedness and inclusiveness, and generate hypotheses on line sharing, rather than to classify the results of a segmentation process. A psychological experiment on 20 subjects is reported, in which some interpretations were exogenously proposed. The constraints in the figure completion and decomposition process are not explained well, and they ignore other gestalt parameters (such as line thickness and orientation).