Advected%20textures

1
Advected textures

• Fabrice Neyret
• EVASION - GRAVIR / IMAG - INRIA
• Grenoble, France

2
Purpose amplifying fluid simulation
3
Purpose amplifying fluid simulation
4
Why not simply increase resolution ?

• Cost N log(N) / time step with N10003
• Storage
• Problems with CFD for CG LamorletteFoster 02
• Unknown small scale phenomena vs artist
  desires phenomenological knowledge

5
Why not simply increase resolution ?

• Cost N log(N) / time step with N10003
• Storage
• Problems with CFD for CG LamorletteFoster 02
• Unknown small scale phenomena vs artist
  desires phenomenological knowledge

6
Why not simply increase resolution ?

• Cost N log(N) / time step with N10003
• Storage
• Problems with CFD for CG LamorletteFoster 02
• Unknown small scale phenomena vs artist
  desires phenomenological knowledge

7
Why not simply increase resolution ?

• Cost N log(N) / time step with N10003
• Storage
• Problems with CFD for CG LamorletteFoster 02
• Unknown small scale phenomena vs artist
  desires phenomenological knowledge

8
Advecting textures

• Advecting u,v MaxBecker 96, Stam 99
• Regeneration
• blending 3 dephased textures (illusion of
  motion)
• latency life duration

9
Problems with texture advection

• Choosing the latency
• Blending textures
• Sub-animation

1 2 3
10
Problems with texture advection

• Choosing the latency
• Blending textures
• Sub-animation

1 2 3
11
Problems with texture advection

• Choosing the latency
• Blending textures
• ghosting effects
• Sub-animation

1 2 3
12
Problems with texture advection

• Choosing the latency
• Blending textures
• Sub-animation

1 2 3
13
Problems with texture advection

• Choosing the latency
• Blending textures
• Sub-animation

1 2 3
14
1. Advecting textures

• A latency value is ok for a range of velocities
  (V)
• bad motion illusion if V lt
• texture stretching if V gt

15
1. Advecting textures

• Adapting latency locally
• Layers of given latency masks

• Local criterion
• cumulated deform particle integral of e
• Target deform d

16
1. Advecting textures

• Adapting latency locally
• Layers of given latency masks

Layer 1 lat1 Layer 2 lat2 (gtlat1) Layer 3
lat3 (gtlat2)

• Local criterion
• cumulated deform particle integral of e
• Target deform d

17
1. Advecting textures

• Adapting latency locally
• Layers of given latency masks

• Local criterion
• cumulated deform particle integral of e
• Target deform d

18
2. Blending textures

• Image textures
• Procedural textures

19
2. Blending textures image textures

• What to do ? (morphing ?)

20
2. Blending textures procedural textures
21
3. Sub-animation

• Flownoise PerlinNeyret 01

22
3. Sub-animation

• Flownoise for sub-scales
• rotations ? vorticity spectrum
• Kolmogorov cascade

23
3. Sub-animation

• Flownoise for sub-scales
• rotations ? vorticity spectrum lt gt
• Kolmogorov cascade

24
3. Sub-animation

• Flownoise for sub-scales
• rotations ? vorticity spectrum lt gt
• Kolmogorov cascade

25
3. Sub-animation

• Vorticity energy transfer through scales
• distribution law for ( power law
  )
• only needs to scale it ( estimate
  )
• Our case
• heterogeneous fluid ( locality -gt no Fourier
  )
• not at equilibrium ( transfer delay -gt
  time )
• user control
• relaxation

26
3. Sub-animation

• Vorticity energy transfer through scales
• distribution law for ( power law
  )
• only needs to scale it ( estimate
  )
• Our case
• heterogeneous fluid ( locality -gt no Fourier
  )
• not at equilibrium ( transfer delay -gt
  time )
• user control
• relaxation (user-defined
  parameters bk and gk )

27
Results
28
Conclusion

• Mixing lo-res CFD and hi-res animated texture
• A model efficient controllable
• Future work
• 3D applications detailed clouds avalanches
• Better flownoise control
• Manage empty space
• Hardware procedural shader

29
Advected textures

• Fabrice Neyret
• EVASION - GRAVIR / IMAG - INRIA
• (Grenoble, France)

30
Sub-animation parameters

• parameters bk and gk
• small b reactive high b inertial
• small g viscous high g light

31
1. Advecting textures
32
3D
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)