Simon Dobbyn
Carol O'Sullivan
ABSTRACT
The simulation of large crowds of humans is important in many fields of computer graphics, including real-time applications such as games, as they can breathe life into otherwise static scenes and enhance believability. We present a novel hybrid rendering system for crowds that solves the classic problem of degraded quality of image-based representations at close distances by building an impostor rendering system on top of a full, geometry-based, human animation system. This enables almost imperceptible switching between the two representations based on a "pixel to texel" ratio, with minimal popping artefacts. Seamless interchanges are further facilitated by exploiting programmable graphics hardware to efficiently enhance the realism and variety of the dynamically-lit impostors, thereby also improving on existing impostor techniques. To test our system, our virtual crowds are embedded in an urban simulation system (as shown in Figure 1). The results demonstrate a system capable of rendering large realistic crowds with the visual realism of a high-resolution geometry rendering system, but at a fraction of the rendering cost.
- Aubel, A., Boulic, R., and Thalmann, D. 2000. Real-time display of virtual humans: Levels of details and impostors. IEEE Transactions on Circuits and Systems for Video Technology 10, 2, 207--217. Google Scholar
Digital Library
- Brogan, D., and Hodgins, J. 2002. Simulation level of detail for multiagent control. In International Joint Conference on Autonomous Agents and Multiagent Systems (AAMAS), 199--206. Google ScholarDigital Library
- de Heras Ciechomski, P., Ulicny, B., Cetre, R., and Thalmann, D. 2004. A case study of a virtual audience in a reconstruction of an ancient roman odeon in aphrodisias. The 5th International Symposium on Virtual Reality, Archaeology and Cultural Heirtage (VAST). Google ScholarDigital Library
- Hamill, J., and O'Sullivan, C. 2003. Virtual dublin - a framework for real-time urban simulation. Proc. of the Winter Conference on Computer Graphics 11, 1--3.Google Scholar
- Loscos, C., Tecchia, F., and Chrysanthou, Y. 2001. Real-time shadows for animated crowds in virtual cities. Proceedings of the ACM symposium on virtual reality software and technology, 85--92. Google ScholarDigital Library
- Luebke, D., Watson, B., Cohen, J., Reddy, M., and Varshney, A. 2002. Level of detail for 3d computer graphics. Elsevier Science Inc. Google ScholarDigital Library
- Musse, S. R., and Thalmann, D. 2001. A hierarchical model for real time simulation of virtual human crowds. IEEE Transactions on Visualization and Computer Graphics 7, 2 (April-June), 152--164. Google ScholarDigital Library
- O'Sullivan, C., Cassell, J., Vilhjálmsson, H., Dingliana, J., Dobbyn, S., McNamee, B., Peters, C., and Giang, T. 2002. Levels of detail for crowds and groups. Computer Graphics Forum 21, 4.Google ScholarCross Ref
- SGI. Nv_fragment_programs. http://oss.sgi.com/projects/ogl-sample/registry/ARB/fragment_program.txt.Google Scholar
- SGI. Nv_register_combiners. http://oss.sgi.com/projects/ogl-sample/registry/NV/register_combiners.txt.Google Scholar
- SGI. Nv_vertex_programs. http://oss.sgi.com/projects/ogl-sample/registry/ARB/vertex_program.txt.Google Scholar
- Shreiner, D., Kuehne, B., True, T., and Grantham, B. 2004. Performance opengl: Platform-independent techniques. In SIGGRAPH '04 Course. Google ScholarDigital Library
- Tecchia, F., and Chrysanthou, Y. 2000. Real-time rendering of densely populated urban environments. Proceedings of the Eurographics Workshop (JUNE), 83--88. Google ScholarDigital Library
- Tecchia, F., Loscos, C., and Chrysanthou, Y. 2002. Image based crowd rendering. IEEE Computer Graphics and Applications 22 (March/April). Google ScholarDigital Library
- Tecchia, F., Loscos, C., and Chrysanthou, Y. 2002. Visualizing crowds in real-time. Computer Graphics Forum 21 (December).Google Scholar
- Ulicny, B., and Thalmann, D. 2001. Crowd simulation for interactive virtual environments and vr training systems. Proceedings of Eurographics Workshop on Computer Animation and Simulation 2001, 163--170. Google ScholarDigital Library
- Ulicny, B., de Heras Ciechomski, P., and Thalmann, D. 2004. Crowdbrush: Interactive authoring of real-time crowd scenes. Proceedings of ACM SIGGRAPH Symposium on Computer Animation (August). Google ScholarDigital Library
Index Terms
- Geopostors: a real-time geometry / impostor crowd rendering system
Recommendations
Maximum mipmaps for fast, accurate, and scalable dynamic height field rendering
I3D '08: Proceedings of the 2008 symposium on Interactive 3D graphics and gamesThis paper presents a GPU-based, fast, and accurate dynamic height field rendering technique that scales well to large scale height fields. Current real-time rendering algorithms for dynamic height fields employ approximate ray-height field intersection ...
A fast relighting engine for interactive cinematic lighting design
SIGGRAPH '00: Proceedings of the 27th annual conference on Computer graphics and interactive techniquesWe present new techniques for interactive cinematic lighting design of complex scenes that use procedural shaders. Deep-framebuffers are used to store the geometric and optical information of the visible surfaces of an image. The geometric information ...
Opacity light fields: interactive rendering of surface light fields with view-dependent opacity
I3D '03: Proceedings of the 2003 symposium on Interactive 3D graphicsWe present new hardware-accelerated techniques for rendering surface light fields with opacity hulls that allow for interactive visualization of objects that have complex reflectance properties and elaborate geometrical details. The opacity hull is a ...
Comments