EVASION

Environnements Virtuels pour l’Animation et la

Synthèse d’Images d’Objets Naturels

Virtual Environments for

Modeling, Animating and Rendering Natural Scenes

INRIA Rhône-Alpes Équipe du laboratoire GRAVIR/IMAG

Future équipe du LJK (CNRS, INPG, INRIA, UJF)

Who are we?

The team

– 6 faculties • 2 full profs : GP Bonneau (UJF), MP Cani (INPG): Scientific leader • 2 assistant profs : F Faure (UJF), F. Hetroy (INPG, sept 2004)• 2 CR1 researchers : F. Neyret (CNRS), L. Revéret (INRIA)

– 4 post-doc, engineer or designer

– 12 PhD students (8 with MENRT grants)

History

– Created in January 2003, after the scission of iMAGIS

– Basis: Computer Graphics (modeling, animation, rendering)

Scientific focus Modeling & Visualizing Nature

• Fascinating problem (vegetable, mineral, animal worlds)

• Still unsolved to a large extent

• Many industrial applications (from realism to real-time)– 3D feature films, Special effects, Video games– Virtual prototyping & Pedagogical Simulators (environment, geology, energy, aeronautics, surgery, cosmetics)

Modeling & Visualizing Nature Main challenges

• Extreme complexity – Number of elements, shape, aspect, motion and deformation

• Re-using models from other sciences is not always possible – Virtual clouds? Fluid dynamics & meteorology study other scales– Hair animation? FEM + collisions not applicable for 100 000 strands

Use existing knowledge: Collaborate with other disciplines Combine efficiency and realism?

Specific methodology + New fundamental tools

Scientific basisMethodology for handling complexity

1. Characterize the observed sub-phenomena

2. Represent them by coupled sub-models– Of different nature : physical model, geometry, texture, ...

– Applied at different scales

3. Dynamically adapt the sub-models to the needs– By changing their local space and time resolution

– By switching from one model to another

4. Validate based on human perception

Methodology for handling complexityExample: meadow blowing in the wind

1. Wind : pattern + action

2. Receever : precomputed dynamics

3. Grass geometry : 3 levels of detail

… [I3D’01,Computer Animation’03]

Contributions1. New fundamental tools

• Geometry– New shape representations

– Interactive deformations

• Animation– Motion control from video analysis

– Physically-based simulation

• Visualization of massive data-sets– Multiresolution analysis & adaptive rendering

• Realistic rendering– Textures, shaders, point-based rendering

New fundamental toolsExample: Constant volume space deformations

• Foldover-free space deformation• Rings of constant volume « swirls » 

Applications• Modeling virtual clay• Animating fluids

[Pacific Graphics’04, SCA’05]

Contributions2. Application to specific natural scenes

• Mineral world– Animation of lava-flows, sea, streams

– Simulation of water, smoke, clouds

• Vegetable world– Real-time rendering of forest

– Animating meadows (grass, trees)

• Animal world– Wild animals animated from video

– Virtual humans: hair, skin, muscles, clothes

– Real-time organs for surgery simulators

Application to specific natural scenesExample: Simulation of Natural Hair

• New Lagrangian deformable model: Super-helices– Predicts the shape of static hair – Efficient and stable simulation of hair dynamics

• Identification of hair interaction parameters• Bridging the gap between wisps & continuum

Interdisciplinary work (cosmetics, mechanics)Industrial partnership (L’Oréal) [EG’05 short, SIGGRAPH’06]

Application to specific natural scenesExample: Simulation of Natural Hair

3. Software development SOFA with CIMIT/Harvard, INRIA, ETHZ, CWU

An Open Framework for Medical Simulation• Multi-institution, international effort • Aim: component sharing / exchange / comparison

Kernel (release Dec 06)

– Communication & interfaces

Modules – FEM, Mass & springs, Particles– Rendering algorithms, – Collision detection & response

Scientific Collaborations

International– Joint team with DGP, University of Toronto (2004-2006) – 6 Eurodoc grants: 6 month visit of PhD students to

U. of Washington, Davis, Berkeley, Calgary, Montreal – European Network of Excellence: Aim@shape(other joint papers with UBC, ETHZ, U. of Tuebingen, UC Davis)

National – Co-advised PhDs: SIAMES, MOVI, APACHE, LMC, TIMC– DEREVE 2 with LIRIS & ICA, MIDAS with TIMC, ICP– ARCs with ALCOVE, EPIDAURE, ISA, Geometrica

with Other Disciplines

2003-2005: Collaborations with the fields of– Mechanics (CEMAGREF, LEGI, L3S)– Medicine (IRCAD, TIMC)– Cognitive Sciences (U. of Geneva)– Cosmetics (l’Oreal research labs)

2005-2009: Interdisciplinary research clusters – “Environnement” & “Santé” (Rhône-Alpes Region)

2006-2009: Multidiciplinary ANR Projects– Biomechanics & Neurosciences (project Kameleon) – Botanics (project NatSim) NatSim

Kamelelon

Industrial grants & transfer

Public projects with technology transfer– European project Odysseous

– RIAM Virtual Actors & RNTL PARI with Galilea

– RIAM projects Vertigo & Prodige with Bionatics and Thales

Direct grants from the industry– L’Oreal (contract 2004-2006)

– CEA / CESTA (PhD grant 2004-2006)

– EDF (PhD grant 2005-2007)

Results & Visibility

• Publications (20 journal, 48 conf, 6 chapters…)

• Editors: GMOD, IEEE TVCG• Conference co-chairs

– EG-IEEE Visualisation’2003, IEEE Shape Modeling & Applications’05

• Paper co-chairs – EUROGRAPHICS’04, ACM-EG Symp. on Computer Animation’06

• PC members– SIGGRAPH, Eurographics, Pacific Graphics

– IEEE Vis, SMI, SCA, CASA, NPAR, etc

Grand challenge ?Specify and control a full, animated natural scene

Creation of digital content, in a difficult case– High number of similar, but different details– Allow user-input / fit specific distributions– Control motion while maintaining realism– Animate and render efficiently

Reasons for tackling it?– Real-size tests & interactions between different phenomena– Interactive exploration (GPU, GRimage PC grid)– Validation through the science of human perception

Objectives for the next 4 years

1. Creation of Natural Scenes• Exploit real images, data, sketching• Combine user control with procedural details

2. Animating Nature: multi-disciplinary projects• Promote interactive virtual scenes as a support for

experimenting and validating hypotheses• Model natural phenomena never achieved in CG

3. Efficient Visualization of very large scenes• Interactive exploration of hybrid data-masses• Fast, realistic rendering of natural scenes

Conclusion

• Computer Graphics group – Competences: modeling, animation, visualization, rendering

– Focus: Virtual natural scenes and phenomena

• Strategic aspects within French research – Combining simulation, visualization and virtual reality

– Processing huge data-sets

– Applications to Environmental simulations

– Applications to Biology/Health-careEVASION

EVASION

Thank you!