title: Detection of surfaces in structure from motion.
abstract: In 3 experiments the authors examined the effects of surface shape on the detection of surfaces in structure from motion displays. In experiment 1 they found the number of points necessary to distinguish simple quadratic surfaces from points randomly placed in a volume to be low, in the range of 4-6 points. In experiment 2 they found that a hyperbolic shape is harder to detect than an arch or parabolic shape and that more curved shapes are easier to detect than less curved shapes. In experiment 3 they found that detection of sinusoidal shapes increases with increasing amplitude and decreasing frequency, confirming previous results with motion parallax displays. This pattern of results is consistent with a model in which triangular surface patches are fit through adjacent triples of points and displays with smaller mean orientation change between neighboring triangles are judged to be surface displays.
authors.affiliation: Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine 92717-5100, USA.
authors.forename: J
authors.initials: J
authors.lastname: Turner
authors.forename: M L
authors.initials: ML
authors.lastname: Braustein
authors.forename: G J
authors.initials: GJ
authors.lastname: Andersen
mesh_terms: D006801:Humans; D009039:Motion Perception