Perception of surfaces from line drawings

We test the perception of 3D surfaces that have been rendered by a set of lines drawn on the surface. Each surface is rendered as a family of curves which are in the simplest case the intersections with a family of parallel planes. On each trial, a surface or its “distorted” version is shown in this way, in an arbitrary orientation on an LCD screen or in a volumetric 3D display. The distortion is produced by stretching the surface in the z-direction by 30%. The subject’s task is to decide whether two sequentially presented surfaces are identical or not. The subject’s performance is measured by the discriminability d′, which is a conventional dependent variable in signal detection experiments. The work investigates the question whether a surface rendered with planar and geodesic curves is easier to recognize than one where the curves are not planar or not geodesic.