Interactive Global Illumination Research Articles

Faster Isosurface Ray Tracing Using Implicit KD-Trees

The visualization of high-quality isosurfaces at interactive rates is an important tool in many simulation and visualization applications. Today, isosurfaces are most often visualized by extracting a polygonal approximation that is then rendered via graphics hardware or by using a special variant of preintegrated volume rendering. However, these approaches have a number of limitations in terms of the quality of the isosurface, lack of performance for complex data sets, or supported shading models. An alternative isosurface rendering method that does not suffer from these limitations is to directly ray trace the isosurface. However, this approach has been much too slow for interactive applications unless massively parallel shared-memory supercomputers have been used. In this paper, we implement interactive isosurface ray tracing on commodity desktop PCs by building on recent advances in real-time ray tracing of polygonal scenes and using those to improve isosurface ray tracing performance as well. The high performance and scalability of our approach will be demonstrated with several practical examples, including the visualization of highly complex isosurface data sets, the interactive rendering of hybrid polygonal/isosurface scenes, including high-quality ray traced shading effects, and even interactive global illumination on isosurfaces.

Interactive rendering of globally illuminated scenes including anisotropic and inhomogeneous participating media

Although new graphics hardware has accelerated the rendering process, the realistic simulation of scenes including participating media remains a difficult problem. Interactive results have been achieved for isotropic media as well as for single scattering. In this paper, we present an interactive global illumination algorithm for the simulation of scenes that include participating media, even anisotropic and/or inhomogeneous media. The position of the observer is important in order to render inhomogeneous media according to the transport equation. Previous work normally needed to be ray-based in order to compute this equation properly. Our approach is capable of achieving real time using two 3D textures on a simple desktop PC. For anisotropic participating media we combine density estimation techniques and graphics hardware capabilities.

A Scalable Approach to Interactive Global Illumination

Abstract The addition of global illumination can dramatically increase the realism achievable when rendering virtual environments.In particular with interactive applications we expect the environment to reflect changes in the scenedue to global lighting effects instead of it being just a static backdrop. However, a sufficiently fast and accuratecomputation of global illumination at interactive rates has been difficult even with recent approaches based onrealtime ray tracing. In this paper we present a highly scalable approach to interactive global illumination. It fully recomputes a high‐qualitysolution for each frame and thus offers immediate feedback even for dynamic scenes, achieving more than20 fps for simple scenes. Compared to previous systems we increased the raw performance by a factor of up toeight and removed the bottlenecks that were limiting scalability. The system now scales linearly in quality andavailable computing resources, tested with up to 48 CPUs in a commodity PC‐cluster. Due to its logarithmicscaling property with respect to scene complexity it even supports lighting simulation in complex scenes with morethan 50 million triangles. This scalability allows applications to perform flexible performance trade‐offs. We alsoargue that the realism achievable through interactive global illumination will make it a standard feature of future3D graphics systems once the required computing resources are readily available.