This Article 
 Bibliographic References 
 Add to: 
Image-Based Crowd Rendering
March/April 2002 (vol. 22 no. 2)
pp. 36-43

Populated urban environments are important in many applications such as urban planning and entertainment. However rendering in real time many people in a complex environment is still challenging. In this article, we propose methods for rendering real-time animated crowds in virtual cities. We take advantage of the properties of the urban environment, and the way a viewer and the avatars move within it, to produce fast rendering, based on positional and directional discretization. To allow the display of a large number of different individual people at interactive frame rates, we combined texture compression with multi-pass rendering. The results show that we can visualize in real time a city with thousands of animated people.

1. F. Tecchia and Y. Chrysanthou, "Real-Time Rendering of Densely Populated Urban Environments," Proc. Rendering Techniques 2000, Springer Computer Science, New York, 2000, pp. 83-88.
2. F. Tecchia et al., "Agent Behaviour Simulator (abs): A Platform for Urban Behaviour Development," Proc. Game Technology (GTEC 2001), CD-ROM, 2001.
3. C. Loscos, F. Tecchia, and Y. Chrysanthou, "Real-Time Shadows for Animated Crowds in Virtual Cities," Proc. ACM Symp. Virtual Reality Software and Technology, ACM Press, New York, 2002, pp. 85-92.
4. F. Tecchia, C. Loscos, and Y. Chrysanthou, "Real Time Rendering of Populated Urban Environments," ACM Siggraph Technical Sketch, ACM Press, New York, Aug. 2001.
1. P.W.C. Maciel and P. Shirley, "Visual Navigation of Large Environments Using Textured Clusters," Proc. 1995 Symp. Interactive 3D Computer Graphics, pp. 95-102, 1995.
2. G. Schaufler and W. Sturzlinger, "A Three-Dimensional Image Cache for Virtual Reality," Computer Graphics Forum, vol. 15, no. 3, Sept. 1996, pp. C227-C235.
3. J. Shade, D. Lischiniski, D. Salesin, T. DeRose, and J. Snyder, "Hierarchical Image Caching for Accelerated Walkthroughs of Complex Environments," Computer Graphics Proc. Ann. Conf. Series (Proc. Siggraph '96), pp. 75-82, Aug. 1996.
4. S.E. Chen and L. Williams, “View Interpolation for Image Synthesis,” Proc. ACM SIGGRAPH '93, pp. 279-288, Aug. 1993.
5. P.E. Debevec, C.J. Taylor, and J. Malik, “Modeling and Rendering Architecture from Photographs: A Hybrid Geometry- and Image-Based Approach,” Proc. SIGGRAPH '96, pp. 11-20, Aug. 1996.
6. L. McMillan and G. Bishop, "Plenoptic Modeling: An Image-Based Rendering System," Computer Graphics, vol. 29, 1995, pp. 39-46.
7. W.R. Mark, L. McMillan, and G. Bishop, "Post-Rendering 3D Warping," M. Cohen and D. Zeltzer, eds., Proc. 1997 Symp. Interactive 3D Graphics, ACM Press, New York, 1997, pp. 7-16.
8. L. Darsa, B. Costa, and A. Varshney, "Navigating Static Environments Using Image-Space Simplification and Morphing," Proc. 1997 Symp. Interactive 3D Graphics, 1997.
9. G. Schaufler, "Per-Object Image Warping With Layered Impostors," Proc. 9th Eurographics Workshop Rendering 98, Springer Computer Science, New York, 1998, pp. 145-156.
10. W.J. Dally et al., The Delta Tree: An Object-Centered Approach to Image-Based Rendering, tech. memo AIM-1604, Massachusetts Inst. of Tech., Artificial Intelligence Laboratory, May 1996.
11. A. Aubel, R. Boulic, and D. Thalmann, "Animated Impostors for Real-Time Display of Numerous Virtual Humans," J.-C. Heudin, ed., Proc. 1st Int'l Conf. Virtual Worlds (VW-98), vol. 1434, Springer, Berlin, 1998, pp. 14-28.
12. A. Aubel, R. Boulic, and D. Thalmann, "Lowering the Cost of Virtual Human Rendering with Structured Animated Impostors," Proc. 7th Int'l Conf. in Central Europe on Computer Graphics, Visualization, and Interactive Digital Media (WSCG 99), Univ. of West Bohemia Press, Czech Republic, Plzen, 1999.
13. F. Tecchia and Y. Chrysanthou, "Real-Time Rendering of Densely Populated Urban Environments," Proc. Rendering Techniques 2000, Springer Computer Science, New York, 2000, pp. 83-88.

Index Terms:
image-based rendering, crowd rendering, virtual cities simulation, texture compression
Franco Tecchia, Céline Loscos, Yiorgos Chrysanthou, "Image-Based Crowd Rendering," IEEE Computer Graphics and Applications, vol. 22, no. 2, pp. 36-43, March-April 2002, doi:10.1109/38.988745
Usage of this product signifies your acceptance of the Terms of Use.