FumeFX for Maya
ver. 4.1  
  Sources  
  FumeFX Sources are the essential elements of any simulation. They are the container for the various aspects of a simulation including temperature, fuel, smoke and the motion for the simulation.

- The Simple Source consists of procedurally created emitter, in a shape of box, sphere or cylinder. It can add fire, smoke, temperature, and velocity to the grid or diminish existing. With a Simple Source, it is easy to create wind, candles, torches, blasts and smoke. For customized emissions within each channel, any 3D procedural texture map can be used as a mask.

- The Object Source can create fire or smoke on any geometric object, which it can treat as solid or hollow. Like the Simple Source, every emitted channel has a mask. Any 2D or 3D texture map can be used (including the ability to use any single RGB component of the map). A simple example of masking is the concept of a fire spreading over a surface controlled by a noise map with animated thresholds.

- The Particle Source uses Maya particle system as the source. Each particle acts like a Simple Source with a given radius. All parameters (radius, channel emissions) have variation per particle. Bezier curves give control over parameters in dependence of the particle age, particle velocity, emiter distance, object distance and expression.

- The FumeFX Source uses another FumeFX simulation as a source for Fuel, Smoke, Temperature, Smoke and Velocity channels.

- As an addition, sources can affect values of any channel by using a special controller that reads voxel data. In practice, this means that sources can emit fuel when temperature (or any other existing data) inside a voxel is above or below a user-defined threshold.