Returns the full path to a particle network context geometry.
An index of 0 corresponds to the first context geometry. This function should only be used from within a particle node.
The POP Network surface node has four inputs to which you can connect geometry. You can then access the connected geometry using this function. This is simply a convenience to let you associate geometry with a particle network without hard-coding node paths.
Pop Merge SOPs might also cook the particular POP network. In that case, this function will give the path of the inputs of the corresponding Pop Merge SOP.