I am have a hard time with masking off an emitter specifically Trapcode Particular from Red Giant. First off is it even possible to achieve? My project is fairly simple, i give static posters "life" for my company to use their ads on TV's I am creating bubbles in the beer glass. I have achieved this but the bubbles go outside the glass because for whatever reason i can;t mask them off... Frustrating to say the least. Any help would be GREAT!
The problem is that AE's render order is confusing for newcomers to the software. You have a couple of different options (but they vary depending on what version of the software you're using.)
If you're using a fairly recent version of AE, you can use the compositing options for the effect.
No matter what version of AE you're using, you can precompose your particle layer (making sure to MOVE ALL ATTRIBUTES into the precomp) and then apply your mask to that precomp in your main composition.