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CNM 190, pt 2CNM 190, pt 2Advanced Digital AnimationAdvanced Digital Animation
Lec Lec 03 : Art Direction on Madagascar / Effects 103 : Art Direction on Madagascar / Effects 1Shannon Jeffries, Shannon Jeffries, PDI/Dreamworks PDI/Dreamworks ((Art Director, MadagascarArt Director, Madagascar))
Marilyn Friedman, Marilyn Friedman, PDI/DreamworksPDI/Dreamworks (Outreach)(Outreach)Dan Garcia, EECS (co-instructor)Dan Garcia, EECS (co-instructor)
Brian Brian BarskyBarsky, EECS (co-instructor), EECS (co-instructor)Greg Niemeyer, Art (co-instructor)Greg Niemeyer, Art (co-instructor)
Jeremy HuddlestonJeremy Huddleston,, EECS (TA) EECS (TA)Ashley EdenAshley Eden,, EECS (TA) EECS (TA)
Jungle shot from Jungle shot from ““MadagascarMadagascar””
2/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
OverviewOverview
ShannonShannon Art directingArt directing
MadagascarMadagascar Critiquing ourCritiquing our
artistic look forartistic look forour two piecesour two pieces
DanDan Special EffectsSpecial Effects
HistoryHistory MechanicalMechanical OpticalOptical
Pure CG film FXPure CG film FX FluidsFluids ParticlesParticles
MarilynMarilyn OpportunitiesOpportunities
@ PDI for you!@ PDI for you!
3/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
Special Effects (SFX) HistorySpecial Effects (SFX) History
The first special effect was done in 1895 who used aThe first special effect was done in 1895 who used adummy to simulate the beheading of Mary Q of Scots!dummy to simulate the beheading of Mary Q of Scots! ““Stop tricksStop tricks”” like this are still used on like this are still used on YouTube YouTube today!today!
Used Used ““when scenes canwhen scenes can’’t be realized by normal meanst be realized by normal means”” In CG animations, very similar case!In CG animations, very similar case! WhatWhat’’s s ““normalnormal””??
en.wikipedia.org/wiki/Special_effectswww.filmsite.org/visualeffects1.html
CGI special effects used in Star Wars Episode IIICGI special effects used in Star Wars Episode III1895: The first SFX!1895: The first SFX!
4/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
Mechanical EffectsMechanical Effects
Aka Aka ““practicalpractical”” or or““physicalphysical”” effects effects Used during live shotsUsed during live shots
These includeThese include Mechanized propsMechanized props SceneryScenery Bullet hitsBullet hits PyrotechnicsPyrotechnics Wind, rain, snow, etcWind, rain, snow, etc
Outside the scope ofOutside the scope ofthis classthis class –– Mech Mech E?E?
en.wikipedia.org/wiki/Special_effects
R2D2 is a mechanical special effectR2D2 is a mechanical special effect
5/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
Optical EffectsOptical Effects
Aka Aka ““visualvisual”” (CGI) or (CGI) orphotographicphotographic””(optical printer) effects(optical printer) effects Manipulations of theManipulations of the
photographed imagesphotographed images
These includeThese include Stop tricks, miniatures,Stop tricks, miniatures,
mattes, dolly zoom,mattes, dolly zoom,bluescreenbluescreen, wire, wireremoval, morphing,removal, morphing,match moving,match moving, andandcomputer-generatedcomputer-generatedimageryimagery (CGI)(CGI)
en.wikipedia.org/wiki/{Special_effects, Optical_printer}
An optical printer used for optical effectsAn optical printer used for optical effects
Apple Shake, for compositing CGI SFXApple Shake, for compositing CGI SFX
6/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
In purely CG films, what are SFX?In purely CG films, what are SFX?
Typically things thatTypically things thatrequire specific technicalrequire specific technicalattentionattention
Natural phenomenaNatural phenomena Smoke,Smoke, fire, fog, snowfire, fog, snow Fluids (water, rain, etc)Fluids (water, rain, etc)
Character-related SFXCharacter-related SFX Cloth simulations, hair, furCloth simulations, hair, fur Footsteps in sandFootsteps in sand Crowds & mobsCrowds & mobs
Often, a problem starts asOften, a problem starts asSFX and evolves into a toolSFX and evolves into a toolthat animators simply usethat animators simply usein the pipeline!in the pipeline!
CG Smoke by Ron CG Smoke by Ron FedkiwFedkiw(with Andrew (with Andrew Selle Selle and Nick Rasmussen)and Nick Rasmussen)
7/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
FluidFluid SimulationSimulation
When to use fluids?When to use fluids? Ocean simulation? No!Ocean simulation? No!
ThatThat’’s easy enough withs easy enough withPerlin Perlin noise and waves ofnoise and waves ofdifferent frequenciesdifferent frequencies((called 2D height fieldcalled 2D height fieldsimulations)simulations)
Typically with mediumsTypically with mediums(fire, smoke, bodies of(fire, smoke, bodies ofwater with water with splashinesssplashiness,,fog, snow driftsfog, snow drifts
Fluids interacting withFluids interacting withother other sims sims (cloth, other(cloth, otherfluids, melting) is hard!fluids, melting) is hard!
graphics.stanford.edu/~fedkiw/www.cs.berkeley.edu/b-cam/
Multiple Interacting Liquids by Ron Multiple Interacting Liquids by Ron FedkiwFedkiw((w/Frank Losassow/Frank Losasso, Tamar , Tamar Shinar Shinar & Andrew & Andrew SelleSelle))
Fedkiw, O’Brien fluid sims
8/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
FluidFluid Simulation BasicsSimulation Basics
Navier-Stokes Navier-Stokes equationsequations These describe the motion ofThese describe the motion of
fluids (liquids & gases)fluids (liquids & gases) Derived from conservation ofDerived from conservation of
mass, energy,mass, energy, angularangularmomentummomentum & momentum& momentum
Momentum equationMomentum equation Really just F=ma, in that itReally just F=ma, in that it
tells you how fluidtells you how fluidaccelerates due to forcesaccelerates due to forcesacting on itacting on it
Incompressibilty condIncompressibilty cond.. Fluid volume in = outFluid volume in = out
AdvectionAdvection is the flow of is the flow ofparticles through field particles through field uu
www.cs.ubc.ca/~rbridson/fluidsimulation/en.wikipedia.org/wiki/Navier_Stokes
IncompressibilityIncompressibility conditioncondition
Momentum equationMomentum equation
uu is velocity is velocity ρρ is density is density
(water = 1000kg/m(water = 1000kg/m33)) pp is pressure is pressure gg is gravity, or is gravity, or ““animatoranimator”” νν is is kinematic kinematic viscosityviscosity
How viscous is fluidHow viscous is fluid ∇∇ pp is pressure gradient is pressure gradient ∇∇ · ·uu is divergence is divergence of velocityof velocity
9/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
FluidFluid Simulation MeshesSimulation Meshes
Lagrangian Lagrangian viewpointviewpoint Moving meshMoving mesh World is a particle systemWorld is a particle system Track where particles goTrack where particles go ““Floating Floating w/wind w/wind in balloonin balloon””
FeaturesFeatures Good for solidsGood for solids Bad for fluidsBad for fluids
Significant deformation andSignificant deformation andtopology changetopology change
www.cs.ubc.ca/~rbridson/fluidsimulation/en.wikipedia.org/wiki/Navier_Stokes
Eulerian Eulerian viewpointviewpoint Static meshStatic mesh Point in space fixedPoint in space fixed Measure as things go byMeasure as things go by ““On ground, wind blowsOn ground, wind blows””
FeaturesFeatures Good for fluidsGood for fluids Bad for solidsBad for solids
Harder to track movingHarder to track movingmaterial quantitiesmaterial quantities
10/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
Particles : cheap & useful!Particles : cheap & useful!
Particle parametersParticle parameters Spawning rate, angleSpawning rate, angle Initial velocityInitial velocity vectorvector Particle lifeParticle life Color and variationsColor and variations Should have noise here!Should have noise here!
SimulationSimulation Update,Update, Render, repeatRender, repeat Friction, objects, gravity,Friction, objects, gravity,
flows (e.g., vector fields)flows (e.g., vector fields)modify location + velocitymodify location + velocity
Particle-particle collisionsParticle-particle collisionsusually not checkedusually not checked
Particle death (fadeParticle death (fade α→α→0)0)
en.wikipedia.org/wiki/Particle_systems
accad.osu.edu/~mpalazzi/AC753W05/Computer%20Graphics%20World%20-%20ANTZ-PIRATION.pdf
11/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
Particles : Particles : ……and ubiquitousand ubiquitous Particles used forParticles used for
Spray, drips, rainSpray, drips, rain surging & pouring watersurging & pouring water DripsDrips ExplosionsExplosions
Particles allow binding!Particles allow binding! One can bind anything to aOne can bind anything to a
particle, very usefulparticle, very useful Particles affect theParticles affect the
surroundings sometimessurroundings sometimes In the shot at the right, waterIn the shot at the right, water
carries objectscarries objects in the hallin the hall RenderingRendering
Metaballs Metaballs commoncommon
www.nextlimit.com/realflow/cs_poseidon.htm
Final composite for Poseidon Final composite for Poseidon ““BroadwayBroadway”” shot shot
CIS Hollywood (small effects house) withCIS Hollywood (small effects house) withearlyearly RealFlow RealFlow rigid body dynamics testrigid body dynamics test
12/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
FluidFluid Simulation SoftwareSimulation Software
MayaMaya (only in(only in Autodesk Autodesk MayaMaya
Unlimited)Unlimited) 2D Solver (height field)2D Solver (height field) 3D Fluid Solver3D Fluid Solver
Realflow Realflow (RF4)(RF4) Python scripting at heartPython scripting at heart Used in many big filmsUsed in many big films Fluids, surfaces, particlesFluids, surfaces, particles
HoudiniHoudini Particle motionParticle motion Fire, white water, insects,Fire, white water, insects,
crowd crowd simssims
www.autodesk.com/mayawww.nextlimit.com/realflow/
www.sidefx.com
Water simulation in Houdini MasterWater simulation in Houdini Master
Software Demos
RF4RF4
13/13Madagascar Art + Effects 1http://inst.eecs.berkeley.edu/~selfpace/CNM190, pt 2
ConclusionConclusion
Particles and Fluids and a world of effectsParticles and Fluids and a world of effects Fluid techniques now readily available in todayFluid techniques now readily available in today’’s SWs SW 2D height fields used for simple ponds, oceans2D height fields used for simple ponds, oceans If solving fluid problem, Euler solution on fixed gridIf solving fluid problem, Euler solution on fixed grid
This is still a very active area of research. ItThis is still a very active area of research. It’’s not solved!s not solved!
Shot from Madagascar with ocean water effects in the background