Crowd Light: Evaluating the Perceived Fidelity of Illuminated Dynamic Scenes

Document type: Journal Articles
Article type: Original article
Peer reviewed: Yes
Full text:
Author(s): Adrian Jarabo, Tom Van Eyck, Veronica Sundstedt, Kavita Bala, Diego Gutierrez, Carol O’Sullivan
Title: Crowd Light: Evaluating the Perceived Fidelity of Illuminated Dynamic Scenes
Journal: Computer Graphics Forum
Year: 2012
Volume: 31
Issue: 2
ISSN: 0167-7055
Publisher: The Eurographics Association and Blackwell Publishing Ltd. Published by Blackwell Publishing
ISI number: 000306181700005
Organization: Blekinge Institute of Technology
Department: School of Computing (Sektionen för datavetenskap och kommunikation)
School of Computing S-371 79 Karlskrona
+46 455 38 50 00
Language: English
Abstract: Rendering realistic illumination effects for complex animated scenes with many dynamic objects or characters is computationally expensive. Yet, it is not obvious how important such accurate lighting is for the overall perceived realism in these scenes. In this paper, we present a methodology to evaluate the perceived fidelity of illumination in scenes with dynamic aggregates, such as crowds, and explore several factors which may affect this perception. We focus in particular on evaluating how a popular spherical harmonics lighting method can be used to approximate realistic lighting of crowds. We conduct a series of psychophysical experiments to explore how a simple approach to approximating global illumination, using interpolation in the temporal domain, affects the perceived fidelity of dynamic scenes with high geometric, motion, and illumination complexity. We show that the complexity of the geometry and temporal properties of the crowd entities, the motion of the aggregate as a whole, the type of interpolation (i.e., of the direct and/or indirect illumination coefficients), and the presence or absence of colour all affect perceived fidelity. We show that high (i.e., above 75%) levels of perceived scene fidelity can be maintained while interpolating indirect illumination for intervals of up to 30 frames, resulting in a greater than three-fold rendering speed-up.
Subject: Computer Science\General
Digital Game Development\General
Keywords: Three-Dimensional Graphics and Realism, Crowds, Lighting, Global Illumination