The Particle Group nodes are automatically created by Phoenix in order to expose several different particle systems (groups) available in only a single node. Such is the case with Phoenix Simulator nodes which load data from Phoenix cache files and can expose several particle systems at once - Foam, Splash, Liquid, WetMap, Mist, or Drag particles. The nodes are named "PGPhoenixFD[...]_[...]" where the first slot is the name of the node that provides the many particle systems, and the second slot is the name of the particle system that is represented, such as Foam, Splash, etc. The nodes can be easily accessed from the Particle Shader's Particle Systems rollout, where all available Particle Group nodes are linked. The Particle Group nodes are required in order for other nodes such as the Phoenix Particle Shader and the Phoenix Source to be able to select only a specific particle system in case more than 1 are available. Particle Group nodes for Foam and Splash are created when enabling Foam and Splash simulation from a Liquid Simulator and accepting the creation of a Particle Shader. Particle System nodes would also be created when selecting a Simulator from a Source or Particle Shader, if the Simulator’s cache sequence (for any frame, not just the current) contains particle systems that don’t have a Particle System node created yet. A Particle Group node can be assigned to a set, or used to create a Maya nParticle System. |