Naiad City Flood: Liquid Art


A recent article in Science, "Computational Physics in Film" reminded me how far we have advanced in computer simulation - all based upon basic physics of fluid dynamics.

Exoticmatter NAIAD City flood from Igor Zanic on Vimeo.

A spectacular example blending fluid dynamics and art: "Naiad City Flood":

Some of the most spectacular examples of physics in film involve fluids, where non-linearities in the underlying Navier-Stokes equations that describe fluid motion lead to accumulation of remarkable geometric complexity.

Computer-based algorithms for animation offers more than speed, efficiency and beauty:

This approach not only is less expensive than filming live action but also can avoid putting actors and crews in dangerous settings and can allow visualization of the impossible.

For the mathematically-inclined, the equation below is used to describe Navier-Stokes:


How did Igor Zanic manage to use fluid dynamics to create this spectacular animation {simulated using 45 million particles)?

According to Igor:

Igor comments on his test (which was his first Naiad simulation):
"Everything was done on i7 950 3.05Ghz with 12GB ram, for this test Naiad use only 4-5GB. The primary fluid simulation comprised 45 million particles (although I could have run a bigger sim on my system) took 32.5 hours, and produced 156.2GB of data."
"28 million secondary splash particles produced 55GB of data. I used Naiad's Particle-Mesh surfacing operator to produce the fluid surface mesh, which weighed in at 20GB for all 300 frames."
"In the end, everything was converted to .bgeo files for Naiad's best companion: Houdini, using Van Aarde Krynauw emp2geo plugin"
"The fluid mesh was rendered with Clay shader, the splash particles were rendered as points with delayed load and deepshadow maps, and the city was render with Mantra PBR."

Can't wait to see what's next? What do you predict?

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Very, very cool. I have played around with another similar package called RealFlow. ( As mentioned, Houdini ( itself also has fluid simulation capability plus all kinds of other physics simulation capability including destruction effects such as fracturing, collapsing and so on.

As a 3D animation and vfx artist myself, yeah, this stuff is fantastic and is getting better and better each year. Plus, the kind of computing power an individual can have sitting on one's desktop in their home office keeps increasing year by year. Right now, I have a Mac Pro with eight processing cores, next year, when Intel ships eight-core processors, I will be upgrading to a 16 core Mac Pro with a graphics card that puts military level graphics capabilities of just s few years ago to shame - for well under $10k. It will be like having a render farm in a box sitting on my desktop.