Believability in simplifications of large scale physically based simulation

We verify two hypotheses which are assumed to be true only intuitively in many rigid body simulations. I: In large scale rigid body simulation, viewers may not be able to perceive distortion incurred by an approximated simulation method. II: Fixing objects under a pile of objects does not affect the visual plausibility. Visual plausibility of scenarios simulated with these hypotheses assumed true are measured using subjective rating from viewers. As expected, analysis of results supports the truthfulness of the hypotheses under certain simulation environments. However, our analysis discovered four factors which may affect the authenticity of these hypotheses: number of collisions simulated simultaneously, homogeneity of colliding object pairs, distance from scene under simulation to camera position, and simulation method used. We also try to find an objective metric of visual plausibility from eye-tracking data collected from viewers. Analysis of these results indicates that eye-tracking does not present a suitable proxy for measuring plausibility or distinguishing between types of simulations. © 2013 ACM.