presentation of lr2v kadi bouatouch irisa email: [email protected]
TRANSCRIPT
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
Application
Application
Application
Application
Application
Application
Rendering Engine
Geometric Model
Appearance Model
RenderingEngine
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
worldcoordinates
scenemodel
nearestintersected
surface
refractedray
reflectedray
shadow“feeler”
ray
Ray Tracing: Principle
Ray Tracing: Principle
View point
Screen
Reflected ray
Shadow ray
Normal Primary ray
Refracted ray
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
Translucency
Example of Volume Rendering
Example of Volume Rendering
Example of Volume Rendering
Example of Volume Rendering
Available Documents
• Available : – Introduction to Computer Graphics– Deterministic Ray Tracing– Texturing– Stochastic Ray Tracing– Volume Rendering
http://www.irisa.fr/prive/kadi/Cours_LR2V/