Computer Graphics World

" e conceptual idea was that the water would move sort of like a swarm of bees, with intelligence but with a life of its own." Sugar and DMG also wanted the water to transition directly from one form to another. It didn't take long for DMG to realize that it was looking at a project that involved some diffi cult water eff ects. "From the moment we fi rst laid eyes on the storyboard, we knew this was going to be one of the most challenging projects we had ever undertaken," says Linds Redding, creative director at DMG. "If we had grasped at the time just how challeng- ing it was, we might well have thought twice about saying 'yes' with such unseemly haste. From the outset, we realized we were going to need some specialist help." at is when Fusion CI became involved. e company is well versed in making advanced fl uid simulations, and to do so, it creates a lot of custom tools for specialty jobs that require more than out-of-the-box solutions. Approximately 60 to 70 percent of the time, clients approach the fi rm to work on "really hard stuff —the simulations that are tricky," says Stasiuk. Water Work Indeed, CG fl uids remain among the most diffi cult eff ects for which to achieve natural looks and behaviors. In this in- stance, the crew needed to push the simulation even further by morphing the water into specifi c shapes. e commercial begins with a puddle of CG water, be- fore the fl uid springs to life into the fi rst shape. From there, the project involves one continuous, 30-second, 650-frame shot, done in a single, complex fl uid simulation within Next Limit's RealFlow. "Fluid looks most realistic and fl uid-like when it is in its natural forms—droplets, puddles, streams, splashes," says Stasiuk. "When you push fl uid into a specifi c geometric shape, you're forcing it to perform unnaturally, while still demanding that it look like fl uid. As the fl uid transforms toward a highly detailed shape, you have to sculpt its mo- tion so that its behavior looks and performs naturally." In addition, says Stasiuk, you have to make sure that only the exact quantity of fl uid that will fi t on the surface of the geometry is attracted to the surface. "If you add too much fl uid or distribute it badly, it will turn into a giant glob, and you won't see the details of the object," he notes. "And once [the water] is on the shape, you don't want it to look like a static ice sculpture, so you have to develop ways of making the fl uid continue to move even as a still object, creating the illusion of fl uid without destroying the details of the geometry. It's tricky." Tricky, yes; impossible, no. And the good news was that Stasiuk did not have to develop the tools needed from scratch. Fusion CI already had a proof-of-concept tool that could form a single shape, something basic, that the facility had built for a previous project. "It was something we could use, but when we got further into this work, we completely rebuilt the tool because the project required so many diff er- ent eff ects and controls. So we ripped [the code] apart and started again." During R&D, the group developed a proprietary fl uid- morphing technology scripted through Python. Stasiuk provides the following before-and-after comparison of the fl uid-shaping tools: e original proof-of-concept tool con- tained 250 lines of code; at the end of this project, the tool contained approximately 1700 lines of code. And all that code formed a proprietary plug-in to RealFlow. August 2009 31 Fluid Simulation ■ ■ ■ ■ Fusion CI Studios created a unique fl uid-simulation plug-in tool to RealFlow for work on a television spot, whereby the water evolves into various recognizable shapes.

• Cover