//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;
}
) 并选择“运行时表达式”(Runtime Expression)(在动力学计算之前或之后)。