Presentation of LR2V Kadi Bouatouch IRISA

Course: LR2V No prerequisite French: Lancer de Rayon, Rendu et Visualisation English: Ray Tracing, Rendering and Visualization

Context Representation and visualization of things which do not exist –Create 3D virtual worlds Choose the model of the objects we want to represent –Visualize them or simulate wave propagation Choose a representation model Choose its appearance Choose a visualization method (rendering) –Animate these worlds

Interest in 3D virtual worlds Computer aided design Manufacturing Movies Entertainment: video games Data Visualization Virtual Reality Working without risk Simulation Acoustics

Application

Rendering Engine Geometric Model Appearance Model Rendering Engine

Rendering Engine Real-time –Z-buffer 10 images per second>>0,1s 25 images per second>>0,04 s 60 images per second>>0,016 s 120 images per second>>0,008 s Non real-time (also for acoustics simul) –Ray Tracing, Path Tracing, Photon Mapping –Radiosity

Ray Tracing: Principle Y X Z eye screen incident ray world coordinates scene model nearest intersected surface refracted ray reflected ray shadow “feeler” ray

Ray Tracing: Principle

Contents LR2V - tronc commun –Deterministic Ray Tracing Geometric computation : intersection, hierarchy of bounding volumes Illumination model: reflection, refraction Acceleration : methods of subdivision into cells: 3D, BSP tree, KD-Tree, Octree, Uniform Grid –Stochastic Ray Tracing: Monte Carlo, stochastic sampling, area light sources, fuzzy reflection, anti- aliasing –Volume Rendering: how to render volume data? Medical Imaging, Scientific Visualization

Reflections If only one reflected ray is considered, then ray- tracing will only handle perfect mirrors.

Reflections Glossy reflections (multiple reflected rays) blur the reflection: use of Monte Carlo method

Translucency

Example of Volume Rendering

Available Documents Available : –Introduction to Computer Graphics –Deterministic Ray Tracing –Texturing –Stochastic Ray Tracing –Volume Rendering