Real-time Animation and Rendering of Ocean WhitecapsOcean Rendering: Wave Models Trochoidal waves...

Real-time Animation and Rendering of Ocean Whitecaps

Real-time Animation and Rendering of Ocean Whitecaps

Jonathan Dupuy, Eric Bruneton

INRIA Grenoble Rhône-Alpes, Université de Grenoble et CNRS, Laboratoire Jean KuntzmannUniversité de Lyon, CNRS Université Lyon 1, LIRIS, UMR5205, F-69622, France

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WhitecapsWhitecaps

spumespume + foam streaksfoam streaks + surface foamsurface foam + bubble cloudbubble cloud

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Deep Water Breaking WavesDeep Water Breaking Waves

Spilling breaker

Plunging breaker

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MotivationMotivationReal time

Movies

Photographs

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Ocean Rendering: Wave ModelsOcean Rendering: Wave Models

Trochoidal waves Fourier transform

ocean surface = horizontally and vertically undulated plane

ocean plane

ocean surface

displacement

[Tessendorf 2001][Tessendorf 2001][Hinsinger et al. 2002][Hinsinger et al. 2002]

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Ocean Rendering: LightingOcean Rendering: Lighting[Bruneton et al. 2010][Bruneton et al. 2010]

mean position position + mean normal normal + slope variancevariance

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Ocean Rendering: WhitecapsOcean Rendering: WhitecapsEmpirical models Particle based

[Darles et al. 2007][Darles et al. 2007] [Chentanez and Müller 2011][Chentanez and Müller 2011]

low quality no control / slow

whitecapswhitecaps

no whitecapsno whitecapssim. domain

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ObjectiveObjective

● Extend Bruneton's lighting model to account for whitecaps– Any viewpoint from ground to space

– Seamless transitions from geometry to BRDF

– Real time

● Context– Deep water waves

– Gaussian heights and slopes

– Spilling breakers only (no overturning)

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Ocean LightingOcean Lighting

●

● Whitecap radiance depends on amount of breaking waves

[Bruneton et al. 2010][Bruneton et al. 2010]

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Breaking WavesBreaking Waves

● Use surface tension– Proportional to jacobian of horizontal displacements

wave profilewave profileillustrative only

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Breaking WavesBreaking Waves

● We use

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Breaking WavesBreaking Waves

wave profilewave profileillustrative only

● Use surface tension– Proportional to jacobian of horizontal displacements

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Breaking WavesBreaking Waves

wave profilewave profileillustrative only

● Use surface tension– Proportional to jacobian of horizontal displacements

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Breaking WavesBreaking Waves

● We use

● depends on Gaussian functions

parameters can be computed analytically for trochoids or through hardware mipmapping for Fourier waves

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Ocean LightingOcean Lighting

●

● Whitecap radiance depends on amount of breaking waves

[Bruneton et al. 2010][Bruneton et al. 2010]

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Ocean LightingOcean Lighting

●

● Whitecap radiance depends on amount of breaking waves

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Results: Quality Results: Quality re

al ti

me

pho

togr

aph

s

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Results: ControlResults: Control

(same surface)

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Results: Scalability / Real TimeResults: Scalability / Real Time

NVidia GeForce 560Ti

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Results: LimitationsResults: Limitations

● Reflectance fluctuations only– No impact on geometry

ex: no plunging breakers

● No decay– Whitecap can last several seconds

● Analytical surface– Repetitive artifacts on periodic surfaces

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ConclusionConclusion

● Ocean scenes with whitecaps in real time– Scalable performance

– Controlable

– Good quality

● Future work– Decay

– Richer whitecap shading model (currently Lambertian / no visibility)

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Real-time Animation and Rendering of Ocean Whitecaps

Real-time Animation and Rendering of Ocean Whitecaps

Jonathan Dupuy, Eric Bruneton

INRIA Grenoble Rhône-Alpes, Université de Grenoble et CNRS, Laboratoire Jean KuntzmannUniversité de Lyon, CNRS Université Lyon 1, LIRIS

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Projected GridProjected Grid

eye

ocean plane

reprojected vertex

reconstructed surface

● Automatic geometrical LOD

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Projected GridProjected Grid

eye

ocean plane

reprojected vertex

reconstructed surface

● Automatic geometrical LOD

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Erf: ApproximationErf: Approximation

erf(x) our approximation

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Erf: ErrorErf: Error

max error: 0.00012