The development of next generation Realtime 3D Libraries is the agenda of the GameTools Project (GTP), an EU project from the 6th Framework Programme. The GTP pushes the envelope in the fields of:

• Geometry
• Visibility
• Global Illumination

The GTP libraries are being developed for next generation PC hardware, with videogame consoles -
PS2, XBox, PS3, XBox 360 - planned as additional hardware platforms.
 

GEOMETRY

Continous Multiresolution Models are a LOD (level of detail) technique in computer graphics which addresses the problem that scenes contain too much geometry when all of the visible objects are rendered at their full geometric resolution. While algorithms along that line have long been available, most modern game/3D-engines implement the much simpler technique of discrete LODs instead. Discrete LOD techniques are widely known for the annoying visible artifacts they produce at the moment the switch between the different resolution models occurs, a drawback unfit for the visual quality of the next generation of 3D/game applications.

The GTP GeometryLib supplies a Multiresolution LOD Solution which addresses the shortcomings of previous approaches by giving developers access to a complete package of solid technology which supplies:

1. A fast image based simplification algorithm to efficiently create high quality MLODs without human intervention.
2. Multiresolution triangle strip generation taking into account topology and texture of the base model.
   Triangle strips are the most efficient way to overcome the bandwidth bottleneck between the main processor and memory on modern high performance graphic cards, thereby vastly speeding up the rendering process.
3. A memory & runtime efficient compressed multiresolution mesh format that contains triangle strip information, avoiding the need for costly on-the-fly tristrip generation.
4. A new multiresolution model specially fitted for plants allowing for an incredible amount of close up detail for e.g. leaves,
   while at the same time supplying simplified representationions for the fast rendering of objects which are further away.

VISIBILITY

In computer graphics, Visibility deals with the problem of rendering faster by rendering only the objects of the scene that can be seen.
Existing solutions along that line employed in modern day 3D/game-engines are mostly based either on Portals or on Quake style PVS (potentially visible set). While these approaches have been successfully employed in commercial products for years, they nonetheless have considerable drawbacks:

1. Both approaches are not suited for outdoor scenes (except scenes which are technically indoor-scenes).
2. It is hard to automatically place portals efficiently, so it normally has to be done by hand.
3. Portals are by nature a very conservative visibility approximation.
4. Portals are not suited for dynamic occluders.
5. For maximum efficiency Quake style PVS is usually done on a scene stored in a BSP tree, which, amongst other drawbacks, is a scene data structure not well suited for dynamically changing scenes.
6. Quake style PVS precalculation can take prohibitively long.

The GTP VisibilityLib will overcome these problems with a 2-phase strategy:

1. A solution which supplies precalculated visibility based on modern visibility research, also suited for outdoor scenes.
2. A solution which efficiently employs modern day graphic hardware to deliver on-the-fly visibility with minimal overhead.

 Both solutions work best when used together, but can also be employed independently from one another, as to best suit the 3D/game engine in use.

GLOBAL ILLUMINATION

Global Illumination is the field of computer graphics that deals with physically correct illumination. Usually this is associated with stochastic raytracing solutions taking hours to calculate a single picture.

The GTP IlluminationLib brings physically correct rendering to the domain of realtime graphics.
Effects that will be possible include:

1. Soft Shadow/Lighteffects
2. Dynamic Lightsources
3. Indirect Illumination
4. Reflections
5. Realtime Radiosity
6. High-Quality Materials (Metal,...)
7. Cloud Rendering

allowing for previously unseen levels of realism in 3D/game applications.