AG 1, AG 2, AG 3, AG 4   Info

AG Audience

-- Not specified --

Saarbrücken

Two elements are essential for rendering realistic images with computer graphics. The first is the accurate modeling of the local behavior of light interacting with individual surface points. The second is the accurate modeling of global light inter-reflections among all surfaces of the scene. In this talk (separated into three main parts), we present our research activities concerning these two topics in the field of realistic rendering. Local interactions are usually modeled with appropriate bi-directional reflectance dirstribution functions (BRDFs). In order to avoid an unrealistic smooth and perfectly uniform aspect, the parameters of the reflectance model are often modulated over the surface by using texturing techniques. In the first part of this talk, we present methods for synthesizing divers textures. We propose a texture analysis and synthesis approach for generating 3D (solid) patterns. In particular, solid textures allow us to avoid the well-known problems of distortions and discontinuities inherent to usual 2D texture mapping. Then, we propose methods for synthesizing and applying ~Sgeometric~T textures to surfaces. ~Sgeometric~T textures, such as bump maps, displacement maps or hypertextures consist of adding some local geometry to the surfaces. We propose analysis and synthesis techniques as well as interactive modeling approaches. Textures characterized by distributed small geometric features are also considered. Finally, texture animation is addressed. In the second part of this talk, we relate textures to BRDFs. A model of inhomogeneous surfaces is proposed by introducing the notion of bi-directional texture function. We also address some topics related to the aging of surfaces, in particular we study the change of appearance due to scratches, which is a defect arising on most common surfaces as these become older. We finally study the particular behaviour of poros materials. The last part of this talk concerns global illumination using a radiosity approach. We introduce the notion of hierarchical virtual surfaces, useful for both, antialiased rendering and global inter-reflections. Then, we integrate the virtual surfaces in hierarchical radiosity algorithms with clustering for computing global solutions. Inter-reflections at texture scale are also considered. Finally, a method of ray tracing the solution is presented based on an optimized final gathering step using solid irradiance estimators and gathering lists.

Marc Stamminger

(0681) 9325 - 422

--email hidden

passcode not visible

logged in users only

Computer Graphics