Issue link: https://digital.copcomm.com/i/5474
10 ■ ■ ■ ■ Viewpoint ods tended to look less organic because the fi nal rendered fl uid was no longer really a fl uid, but a highly massaged particle cloud. Smorganic fl uids, on the other hand, are all fl uid, all the time. In concept, the method is simple. As the fl uid moves, the algorithm searches through the particle cloud and calculates a parameter called the divergence. e divergence is the rate at which fl uid is fl owing away from a point. e algorithm focuses on divergent areas and determines when a gap opens up between two particles. At that point, a new par- ticle is popped into the hole. e key to getting this to work is under- standing exactly when it's safe to add a particle without increasing the pressure in the surrounding fl uid. at would lead to a fl uid explosion at worst, and ugly jitter at best. By doing this insertion process grace- fully, smorganic creates beautiful and delicate fl ows that won't break apart and will render smooth as silk. e process is so stable that there need be no reliance on having a signifi cant thickness of fl uid in the fi rst place to buff er the algorithm in case it can't keep up. is means that even the thinnest possible sheets of fl uid—a single particle thick—can be generated and manipulated. New tools always inspire yet more tools. e process of tracking in- ter-particle displacements allows you to choose to fi ll in the holes to a greater or lesser extent. is means you can control precisely where and when the fl uid breaks apart, and how quickly it does so. Another useful by-product of the process is the ability to track how particles are distrib- uted around one another. With a little extra work, you can identify the edge of the fl uid. is domain of fl uid is otherwise hard to reliably fi nd, but it's extremely important for additional eff ects. For example, really thin sheets of fl uid in air have an edge with a dis- tinctly thickened lip, and often there are small droplets emanating from those edges. e reality is that the lip and droplets are part of a surface- tension-driven process of the fl uid sheet starting to disrupt. Although the smorganic process doesn't simulate that disruption (yet), we can use a knowledge of the fl uid margin to create the needed visuals. By increas- ing the weighting at the edge for the metaball-based mesh, we can gen- erate as sexy a thickened lip as the most botoxed starlet on the Sunset Strip. And we can emit more fl uid from the lip to form droplets—as many as are wanted—to get the fi nal level of detail. at kind of reliable directability is what we strive for in our work, as it's the foundation to achieving the right look within tight production schedules. Smorganic moves us closer to real fl uid behaviors and demonstrates the future direction in the fi eld: extreme directability. As a result, our clients now have a solid alternative to the tabletop shoot. Green is in these days, so we like to think of smorganic as our contribution toward a better, greener world—let's save that water for drinking, rather than splashing it over and over again under hot spotlights. ■ December 2009 Fusion CI Studios' Smorganic tool smooths SPH particle sims dynamically during the process, enabling small-scale fl uid fl ow to continue naturally.