Fundamentals. The Art of Rendering (updated) The Science of Fluid Sims. Fluid sims have become such a vital part of so many visual effects films, yet are not well understood by most general artists. We try and explain the science behind the fluid sims, and look at one in particular closely: Naiad, with help from our friends at Exotic Matter. Introduction One of the most significant and commonly requested areas of real world simulation is fluid simulation.
From pouring shots to ocean vistas, directors and artists have come to rely on computer simulated water and similar fluids. Fluid dynamics is a complex area and fluid simulations are notoriously computationally expensive, yet when they work they can provide magnificent production value and breathtaking visual effects. Fluid sims are not confined to just fluids either, they can be used to achieve fire and flames - the fluid being simulated in this scenario is the air itself (a gas). Fluid simulations (fluid sims) have many applications outside visual effects. History - Watch Jerry Tessendorf talk at TED. Science of Fluid Sims: Pt 2 – RealFlow. Last September we published a piece on fluid sims. The aim was to examine the topic via one primary approach. Here is a second companion piece to that original story that examines the topic via the work of Fusion CI Studios.
Mark Stasiuk and Lauren Millar are co-founders of Fusion CI Studios, a dynamic effects specialist facility that uses RealFlow extensively. Millar is a filmmaker of 20 years’ experience, having produced or directed more than 75 TV shows, and Stasiuk holds a PhD in geophysical fluid mechanics. They met at a volcanic eruption in Monterrat in the late 90s. Today, she is the executive producer and he the VFX supervisor at Fusion CIS. Stasiuk started using RealFlow and answering questions on the forums with such insight that RealFlow’s authors at Next Limit began noticing. . - Above: watch Fusion CI’s demo reel. Stasiuk has a doctorate from Bristol University in fluid dynamics of volcanic eruptions. “We called him Dr. RealFlow - Above: watch a RealFlow demo reel.
Polygonization. Art of Destruction (or Art of Blowing Crap Up) Destruction pipelines today are key aspects of any major visual effects pipeline. Many current pipelines are based on Rigid Body Simulations (RBS) or otherwise referred to as Rigid Body Dynamics (RBD), but a new solution – Finite Element Analysis (FEA) – is beginning to emerge. In this ‘Art Of’ article, we talk to some of the major visual effects studios – ILM, Imageworks, MPC, Double Negative and Framestore – about how they approach their destruction toolsets. In VFX and CGI, RBS is most often relevant to the subdivision of objects due to collision or destruction, but unlike particles, which move only in three space and can be defined by a vector, rigid bodies occupy space and have geometrical properties, such as a center of mass, moments of inertia, and most importantly they can have six degrees of freedom (translation in all three axes plus rotation in three directions).
The ‘explosion’ in destruction tools A scene from '2012', visual effects by Digital Domain. Another scene from 2012.