Densely Populated Urban Environments

Overview

The general idea here is to come up with techniques for visualising, in real-time, large urban environments which are populated with as many dynamic entities (humans, cars etc) as desired. 
We will look at various relevant issues such as collision detection, rendering of the animated avatars, improved illumination, occlusion culling and simulation of pedestrian movement.

 Two EPSRC projects contributed funding for most of the initial work: project GR/R01576/01 with Yiorgos Chrysanthou as principle investigator and Franco Tecchia as research fellow, and the Equator IRC project on which Celine Loscos was a research fellow.

Some Results

We currently have a robust real-time system that can render thousands of animated avatars in an urban environment, with a good degree of realism. The following images can give you an idea of what we have. For more images and videos please follow these two links: SIGGRAPH01 sketch, VRST01 paper.

Of course there is still plenty work to be done. Some of the areas we are currently working on is better behavior simulation, better illumination of the impostors, and occlusion culling for the dynamic environment.  More results on these should be out shortly. 

Papers

	Collision Detection: F. Tecchia and Y.Chrysanthou, Real-time Visualisation of Densely Populated Urban Environments: a Simple and Fast Algorithm for Collision Detection, Eurographics UK, Swansee, April 2000.
	Basic idea on avatar impostors: F. Tecchia and Y. Chrysanthou, Real-Time Rendering of Densely Populated Urban Environments, Eurographics Rendering Workshop 2000.
	A bit about behavior: F. Tecchia , C. Loscos, R. Conroy, Y. Chrysanthou, Agent Behaviour Simulator (ABS): A Platform for Urban Behaviour Development, GTEC’2001, Hong Kong, January 2001.
	Short overview of the system as it was in 2001, including occlusion culling: F. Tecchia, C. Loscos, Y. Chrysanthou, Real Time Rendering of Populated Urban Environments, ACM Siggraph'01, technical sketch, Los Angeles, California, USA, August 2001.
	Shadows for the impostors: C. Loscos, F. Tecchia, Y. Chrysanthou, Real Time Shadows for Animated Crowds in Virtual Cities, ACM Symposium on Virtual Reality Software & Technology 2001 (VRST01), Banff, Alberta, Canada, November 2001.  pdf paper (809kb)
	Alpha testing and texture compression for increased variety: Franco Tecchia, Celine Loscos and Yiorgos Chrysanthou.  Image-Based Crowd Rendering. IEEE Computer Graphics and Applications, volume 22, number 2, March-April 2002.
	Per pixel lighting + general overview: Franco Tecchia, Celine Loscos and Yiorgos Chrysanthou.  Visualizing Crowds in Real-Time. Computer Graphics forum, Volume 21, Number 4, December 2002, pages 753-765.
	High level behaviour: D. Michael and Y. Chrysanthou. Automatic High Level Avatar Guidance Based on Affordance of Movement. Short paper in Eurographics 2003, Granada, Spain, September 2003.