//RUN TIME EXPRESSION FOR REMOVING PARTICLES AFTER THEY REACH //10 ON Y AXIS //GET THE POSITION OF PARTICLES vector $pos= particleShape1.position; //CHECK TO SEE IF THEY HAVE PASSED A CERTAIN Y VALUE (10 in this example) if ($pos.y>=10) { int $pi=particleId; //PRINT IDs OF PARTICLES TO BE REMOVED print ($pi+"\n"); particle -e -at lifespanPP -id $pi -fv 0 particle1; }