Stereoscopy for visual simulation of materials of complex appearance

Abstract : The present work studies the role of stereoscopy on perceived surface aspect of computer generated complex materials. The objective is to investigate if, and how, the additional information conveyed by the binocular vision affects the observer judgment on the evaluation of flake density in an effect paint simulation. We have set up a heuristic flake model with a VoronoÏ modelization of flakes. The model was implemented in our rendering engine using global illumination, ray tracing, with an off axis-frustum method for the calculation of stereo pairs. We conducted a user study based on a flake density discrimination task to determine Perception Thresholds (JNDs). We obtained small JNDs variations when expressed on Weber fractions: 3.62%, and 3.45% for the monoscopic- and for the stereoscopic-condition. Our results are discussed on the basis of the flake density scale obtained by morphology image processing techniques.