anyone can tell me what difference with particle sop and popnet sop .and what shall i do to make spiral force and vortex force field in popnet.

Hi leo3d,

The Particle SOP is the predecessor of POPs. It can still be used to create particles but you do not have as much control & as many features as POPs.

With regards to your questions about forces, please download the legacy tutorials from here [sidefx.com]. There are also other legacy tutorials available from the Learn section of the SESI Community [sidefx.com].

Cheers!
steven

thank you very much ,stev enong