Abstract : Nowadays, computer generated images can be found everywhere, through a wide range of applications such as video games, cinema, architecture, publicity, artistic design, virtual reality, scientific visualization, lighting engineering, etc.
Consequently, the need for visual realism and fast rendering is increasingly growing.
Realistic rendering involves the estimation of global illumination through light transport simulation, a time consuming process for which the convergence rate generally decreases as the complexity of the input virtual 3D scene increases.
In particular, occlusions and strong indirect illumination are global features of the scene that are difficult to handle efficiently with existing techniques.
This thesis addresses this problem through the application of discrete shape analysis to rendering.
Our main tool is a curvilinear skeleton of the empty space of the scene, a sparse graph containing important geometric and topological information about the structure of the scene.
By taking advantage of this skeleton, we propose new methods to improve both real-time and off-line rendering methods.
Concerning real-time rendering, we exploit geometric information carried by the skeleton for the approximation of shadows casted by a large set of virtual point lights representing the indirect illumination of the 3D scene.
Regarding off-line rendering, our works focus on algorithms based on path sampling, that constitute the main paradigm of state-of-the-art methods addressing physically based rendering.
Our skeleton leads to new efficient path sampling strategies guided by topological and geometric features.
Addressing the same problem, we also propose a sampling strategy based on a second tool from discrete shape analysis: the opening function of the empty space of the scene, describing the local thickness of that space at each point.
Our contributions demonstrate improvements over existing approaches and clearly indicate that discrete shape analysis offers many opportunities for the development of new rendering techniques.
Tuesday 15th of December 2015 at 10 am, in the Amphi 160 to ESIEE Paris.