In almost every conversation I had about the differences between 3ds Max and Maya, I used to bring up Max’s lack of a fluid dynamics system. But that’s a thing of the past since Sitni Sati, the brilliant boys in Croatia and the developers of AfterBurn and DreamScape, have developed FumeFX, the answer to Max’s fluid dynamics void.
Now, to clarify for the uninitiated, ‘fluid’ doesn’t necessarily mean ‘water.’ In fact, FumeFX is specifically based on gaseous fluids which abide by laws of fluid dynamics. In this Fume world, the calculations attempt to replicate the real world, and it’s a very different place than what we are used to with particle systems. You have to wrap your mind around how temperature, fuel, buoyancy and such work with gases. Yet FumeX attempts to make it easy enough so that you don’t have to have a degree in thermodynamics to use the product.
In simple terms, the idea is to set up a fuel source with parameters in the scene that will cause it to ignite into a burning state and ultimately into smoke. Each of these stages can be isolated so that you might have just a flame on a Bunsen burner or just smoke swirling off the tip of a cigarette. All of this happens in a set volume, which shrinks or grows to accommodate the size of the sim. So, in the beginning, when the ignition of the fuel takes place, the volume is smaller. Then it expands during and after the reaction. The dynamic quality of the volume makes the calculations more efficient. Each part of the simulation’fuel, fire, smoke, etc.’is written out to the hard drive as a cache, which is then utilized for rendering or as a starting point for new simulations.
The illumination and rendering of the fluid is handled within Max but is tailored to work with FinalRender and its global illumination. Not only can you light the Fume fluid using standard techniques, but the fluid itself can generate light from the fire/explosion and illuminate itself and, with the GI component turned up, can be a light source on other objects in the scene. Additional particle systems in Max like Particle Flow and Thinking Particles have been integrated well into FumeFX. Particle systems can affect the fluid calculations and can also be affected by the simulation so they can follow the currents in the fluid. Within Thinking Particles, they can be probed for value and controlled by channel values (temperature, velocity, etc.), and depending on the result, additional particle events or even additional Fume events, can be activated.
Sitni Sati has provided FusionWorks, an environment render assistant to get around a big problem with Max’s atmospheres. Normally, Max does not have the ability to mix different types of atmospheres’fog and smoke from two different systems, for instance. Each atmosphere is rendered on top of the previous based on its position in the environment list. FusionWorks allows you to blend different Fume sims together. It will also allow blending of other Sitni Sati products like AfterBurn, ScatterVL Pro, and DreamScape’with Max’s internal fog system to boot.
I’m a huge proponent of a program having some kind of scripting so the end user can modify the base functionality and create ways for data to be used with other programs in other ways. FumeFX does not skimp in this area either. It comes with a wide library of MaxScript commands to read and write data to and from the simulation, which additional integration with Thinking Particles.
Before you dive headfirst off the cliffs of Acapulco into the shallow waters of fluid dynamics, you must understand that re-creating physics is slow at best, excruciating at worst. FumeFX offers no easy solutions. Despite its optimizations including writing out illumination maps, caching simulations, control over voxel and grid sizes, Fume is not for people with short attention spans. You have to often run many variations on a simulation to get it right, and each simulation can take hours. I’m working on a show right now where a simulation has taken days. Granted, this might be an extreme, but I don’t think this is unusual. To clarify, I am not faulting FumeFX and Sitni Sati’s efforts in the least. The results are phenomenal and the control you have as a user are terrific. I am simply saying that because of the nature of what Fume is accomplishing, you can expect long simulations, high-memory utilization (so beef up that RAM’on a 64-bit system preferably that will use more than 2GB), and vast amounts of storage for simulation caches and other items like illumination maps. In short, it’s a fantastic program, but not for the faint of heart!