Experiments with random-dot masking demonstrate that, in the absence of cues mundanely available to 2-D displays (object occlusion, surface shading, perspective foreshortening, and texture gradients), Holografika's large-screen multi-projector video system (COHERENT-IST-FP6-510166) elicits useful stereoscopic and motion-parallax depth cues, and does so in under 2 s. We employed a simplified version of Julesz's (c. 1971) famous spiral ramp surface: a 3-layer cylindrical wedding-cake--via an openGL model that subjects viewed along its concentric axis. By adjusting its parameters, two sets of model-stimuli were rendered: one with a uniform large field of depth and one where the field was effectively flat. Each of eleven, pre-screened, subjects completed four experiments, each consisting of eight trials in a 2IFC design whereby they indicated in which interval they perceived the greatest field of depth. The experiments tested one-eye static, one-eye head-swaying, two-eye static, and two-eye head-swaying observation--in that order. Scores improved also in that order.
