Section: Scientific Foundations
Visual rendering
- Global illumination :
direct and indirect illumination computation.
- Rendering:
computation of an image of a virtual world as seen from a camera.
- Partitioning :
subdivision of a 3D model into cells.
- Client-server :
a server contains complex 3D scenes, a client sends requests for objects to the server.
- GPU :
Graphics Processing Unit.
High fidelity rendering requires the use of a global illumination model that describes the light transport mechanism between surfaces, that is, the way every surface interacts with the others. Therefore, the global illumination model is a key problem when accuracy is needed in the rendering process (photorealism or photo-simulation) and is no more than an integral equation to be solved:
where L() is the radiance, nx is the normal of the surface at location x , Le the self-emitted radiance, x a point on a surface, 
the incident direction, 
the
outgoing direction, and d
the differential solid angle around the incident direction.
Computing global illumination amounts to solve this integral equation. Unfortunately, this is still a demanding process in terms of memory and computation resources. Our objective is to propose methods that would perform global illumination computation interactively and in real-time. Our methods rely on the radiance caching mechanism and exploit the performances of the new graphics cards (GPU) even in case of complex scenes. We are also interested in subsurface scattering (for modeling and rendering translucent objects such as human faces) and in the modeling and rendering in real-time of large natural scenes.
