Computer graphics, and the underpinning theory developed in the field of computational geometry, is key to a great many commercial systems ranging from engineering design and manufacture through the games and film industries to surgical simulators.
Currently the Computer Graphics Project has a particular interest in: automatic and interactive urban modelling, rendering acceleration for large populated urban models, crowd simulation, haptic rendering, medical visualisation and multi-modal visualisation including sound and touch.
Google Earth has raised the profile of geospatial data and 3D maps and brought the challenges of managing the trade-off between speed and detail and also the semi-automatic capture of data once more into focus. The graphics group is addressing these challenges in a number of ways. Day is using tiled quad trees to improve compression rates whilst maintaining real-time rendering speeds. Pre-processing data, to reduce redundant memory accesses, significantly reduces the demand for memory-to-chip bandwidth. At the map level, by combining recognisably geometric shapes in images of urban scenes with recent methods for projective reconstruction, Day and his group have improved the registration of images into coarse 3D models to produce photorealistic urban models.
The group is now semi-automatically populating the, often historical scenes, with moving virtual humans (EPSRC award, EP/E035639/1 £276k, 2007). Here, the group distinguishes between image based imposters (that replace small scale detailed geometry) for the crowds and traditional, polygonal, virtual humans with a high-level of detail. For practical, real-time, applications of these algorithms the group is integrating efficient scene graphs with culling, impostors and the exploitation of hardware pixel shaders to create commercial products.
The research is exploited through the Urban Modelling Group.
Using a mouse to interact with 3D objects on the screen is limiting. An alternative is a "3D pen" with force feedback, or haptic feedback. Day and Laycock are contributing to research in this area. A critical element is fast collision detection and the group has contributed a new algorithm. Haptic feedback is particularly relevant to the simulation of surgery for teaching. Lapeer's work on augmented reality for surgical navigation, keyhole surgery in particular, arises from a longstanding collaboration with University College London and now the Norfolk and Norwich University Hospital. In this collaboration he is currently integrating haptics with improved models of skin modelling (derived from experimental stress tests). One goal of the graphics group is to become a leader of research into the enriched human-computer interface enabled by haptics.
CGP collaborates with groups including: John Innes Centre, University of Stuttgart, Technische Universitaet Braunschweig, in Brazil, Universidade de Sao Paulo, and in China, Zhejiang University, Hangzhou.