Modelling Realistic Modelling Realistic Water & FireWater & Fire
Sérgio LealSérgio Leal Socrates/Erasmus student at:Socrates/Erasmus student at:
AK Computer GraphicsAK Computer GraphicsInstitute for Computer Graphics and VisionInstitute for Computer Graphics and Vision
Technical University of Graz Technical University of Graz 2002/20032002/2003
[email protected]@sbox.TUGraz.at
IntroductionIntroduction
Why model realistic Water and Fire?Why model realistic Water and Fire? ApplicationsApplications How to modelHow to model Similarities and differencesSimilarities and differences ConclusionConclusion
Why model Water & Why model Water & Fire?Fire?
Better Visualisation and understanding Better Visualisation and understanding of Physical/Natural Phenomenaof Physical/Natural Phenomena
Film IndustryFilm Industry VRVR Pure PleasurePure Pleasure
By Sérgio LealBy Sérgio Leal
Applications - EngineeringApplications - Engineering
Model realistic physical movements Model realistic physical movements and object interactionsand object interactions
Better understanding of physical Better understanding of physical phenomenaphenomena
Better calculation of human Better calculation of human constructions and nature interactionsconstructions and nature interactions
Applications - AnimationApplications - Animation
Visualisation on the process of learning Visualisation on the process of learning VRVR FilmFilm ArtArt
Image from [Enright et al. 2002]Image from [Enright et al. 2002] By Sérgio LealBy Sérgio Leal
How to model?How to model?
The Navier-Stokes EquationsThe Navier-Stokes Equations Conservation of the massConservation of the mass
∆ ∆ .u = 0, where u is the liquid velocity field .u = 0, where u is the liquid velocity field and on 3D, ∆ = and on 3D, ∆ = (δ/δx, δ/δy, δ/δz)(δ/δx, δ/δy, δ/δz)
Conservation of the momentumConservation of the momentum ut = ν ∆∙ (∆u) - (u∙∆)u-(1/ ρ )∆p +g, where ν
is viscosity, ρ is density, p is pressure and g is gravity
How to model Water?How to model Water?
[Foster and Fedkiw [Foster and Fedkiw 2001]2001] Define a containerDefine a container Cells can be empty or Cells can be empty or
solidsolid Liquid can only occupy Liquid can only occupy
the empty/unfilled cellsthe empty/unfilled cells Represent liquid using Represent liquid using
implicit surfacesimplicit surfaces Smooth surface with Smooth surface with
dynamic isocontourdynamic isocontour Volume modeling Volume modeling
Image from [Foster and Fedkiw 2001]Image from [Foster and Fedkiw 2001]
How to model Water?How to model Water?
[Enright et al. 2002][Enright et al. 2002] Improved Improved [Foster and [Foster and
Fedkiw 2001] modelFedkiw 2001] model New front tracking New front tracking
technique for Water technique for Water surface representation surface representation
Velocity extrapolationVelocity extrapolation Better Water surface Better Water surface
effecteffect Surface modeling Surface modeling Refraction on the light Refraction on the light
impression improved impression improved
Image from [Enright et al. 2002]Image from [Enright et al. 2002]
How to model Fire?How to model Fire?
[Nguyen et al. [Nguyen et al. 2002]2002] Represent the Represent the
expansion of the expansion of the vaporized fuel vaporized fuel
Smoke, black radiance Smoke, black radiance and the blue core and the blue core
Chemical reactionChemical reaction Implicit surfaceImplicit surface Incompressible flowIncompressible flow Stable fluidsStable fluids
Image from [Nguyen et al. 2002] Image from [Nguyen et al. 2002]
SimilaritiesSimilarities
Both are implicit Both are implicit surfacessurfaces
Physical based Physical based modelsmodels
Can be described as Can be described as a fluid like a fluid like movementmovement
Semi-Lagrangian Semi-Lagrangian Stable Fluids Stable Fluids approachapproach
Image from [Nguyen et al. 2002]Image from [Nguyen et al. 2002]
Image from [Foster and Fedkiw 2001]Image from [Foster and Fedkiw 2001]
DifferencesDifferences
WaterWater Computational fluid dynamicsComputational fluid dynamics ReflectionReflection Tend to be stableTend to be stable
Fire Fire Incompressible flowIncompressible flow Very instableVery instable Chemical reactionChemical reaction SmokeSmoke RadianceRadiance
[Nguyen et al. 2002][Nguyen et al. 2002]Image from [Enright et al. 2002]Image from [Enright et al. 2002]
ConclusionConclusion
Very fascinatingVery fascinating A lot to be doneA lot to be done Many applicationsMany applications
By Sérgio LealBy Sérgio Leal
ReferencesReferences PapersPapers
Enright, D. Marschner, S. and Fedkiw, R. 2002. Animation and Enright, D. Marschner, S. and Fedkiw, R. 2002. Animation and Rendering of Complex Water Surfaces. Rendering of Complex Water Surfaces. iin n Proceedings of SIGGRAPH Proceedings of SIGGRAPH 2002.2002.
FOSTER, N. and FEDKIW, R. 2001. Practical animation of liquids.FOSTER, N. and FEDKIW, R. 2001. Practical animation of liquids. i in n Proceedings of SIGGRAPH 2001Proceedings of SIGGRAPH 2001, ACM Press / ACM SIGGRAPH, E. , ACM Press / ACM SIGGRAPH, E. Fiume, Ed., Computer Graphics Proceedings. Annual Conference Fiume, Ed., Computer Graphics Proceedings. Annual Conference Series, ACM, 23–30.Series, ACM, 23–30.
Nguyen, D. Q. Fedkiw, R and Jensen, H. W. 2002. Physically Based Nguyen, D. Q. Fedkiw, R and Jensen, H. W. 2002. Physically Based Modeling and Animation of Fire. Modeling and Animation of Fire. iin n Proceedings of SIGGRAPH 2002Proceedings of SIGGRAPH 2002..
Images Images WaterWater
Enright, D. Marschner, S. and Fedkiw, R. 2002.Enright, D. Marschner, S. and Fedkiw, R. 2002. Leal, S. 2003Leal, S. 2003
FireFire Nguyen, D. Q. Fedkiw, R and Jensen, H. W. 2002.Nguyen, D. Q. Fedkiw, R and Jensen, H. W. 2002. Leal, S. 2003Leal, S. 2003
Thank you for your Thank you for your attentionattention
Modelling Realistic Water & FireModelling Realistic Water & Fire
Sérgio LealSérgio Leal Socrates/Erasmus student at:Socrates/Erasmus student at:
AK Computer GraphicsAK Computer GraphicsInstitute for Computer Graphics and VisionInstitute for Computer Graphics and Vision
Technical University of Graz Technical University of Graz 2002/20032002/2003
[email protected]@sbox.TUGraz.at