How Mesoscale and Microscale Roughness Affect Perceived Gloss

We have studied how perceived gloss varies with the change of both mesoscale and microscale roughness on 3D surface textures. The mesoscale roughness was changed by varying the roll-off factor (β) of 1/fβ fractal noise surfaces. The microscale roughness was changed by varying the microscale roughness parameter α in the microfacet reflection model. An HDR real-world environment map was used to provide complex illumination and a physically- based path tracer was used for rendering the stimuli. Each simulated surface was rotated about its vertical axis to generate an animated stimulus. Eight observers took part in a 2AFC experiment, and the results were tested against conjoint measurement models. We found that the perceived gloss changes non-monotonically with β (an asymmetric bell curve), and monotonically with α. Although both β and α significantly affect perceived gloss, the additive model is inadequate to describe their interactive and nonlinear influence, which is at variance with previous results [1]. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down.