PhoenixFD Test operator
This PF operator checks the fluid in the particle's position and if the value of the selected channel is above/below a given threshold redirects the particle into a different event.
Phoenix node (MXS: node) - determines which simulator will be used.
Source channel (MXS: srcchannel) - determines which channel will be used.
Level (MXS: level) - specifies the threshold level.
Variations (MXS: var) - specifies variations in the level in absolute values.
True if below (MXS: invert) - inverts the behavior of the test.