“Persistence and propagation of shadow direction in mobile and multi-device graphics” by Yau, Moore, Ji, Roland and Tomlinson

Multi-Device Virtual Environments (MDVEs) – in which several collocated graphical computing devices integrate together to form a single virtual world – are a novel area for applications in entertainment, education and simulation. MDVEs composed of stationary and mobile devices, though, pose new challenges in the area of lighting design. Traditional computational lighting design techniques are static and do not take into account physical movement of the device. However, static light design does not work well in mobile devices; for example, the shadows in the environment remain static even if the user rotates the device. This paper addresses this challenge by attaching sensing devices to mobile computers to detect their physical movements. The MDVE then uses this feedback to adjust the virtual light source so that it remains consistent with how light sources work in real world. This lighting model may then be propagated via IrDA among the devices in the MDVE. By improving lighting in MDVEs, this research seeks to bridge the gap between the real world and a virtual world and to help enhance the believability of MDVEs.

1. Tomlinson, B., Yau, M. L., O’Connell, J., Williams, K. and Yamaoka, S., 2005. The Virtual Raft Project: A Mobile Interface for Interacting with Communities of Autonomous Characters, In Conference Abstracts and Applications, ACM Conference On Human Factors In Computing Systems (CHI 2005).