Problem importing particles

[jeff-stanislawski]

hey everyone,
i have a problem i can't seem to figure out and was hoping someone could help me.
i have a few versions of some simple particle smoke that i want to place around some chimneys in this little town. so i have 3 different maya files with just the particle simulatons in them and when i try to import them into the maya file with the town. the particles don't show up when i hit play. the emitter and fields show up, as well as the particle node but nothing comes out of the emmiter.
i'm still fairly new to the dynamics stuff so i'm sure it's something i'm doing wrong, i was just hoping someone could tell me what. thanks.

jeff

(i'm using maya 2010 by the way)

[thnkr]

Here's a simple expression that does that. Adjust fps to match the number of frames per second you're using and set the frequency to the number of puffs per second you want and the set amplitude to the number of particles.

float $fps = 24;
float $pi = 3.14159265;

float $amplitude = 100.0;
float $frequency = 1;
emitter1.rate = ((sin(((frame*$frequency)/$fps)2.0$pi)+1.0)/2.0) * $amplitude;