I'm trying to find particle plugins that allow the use of Illustrator/PSD/image files for the particles, allow you to adjust the scale of the particles, but are free. <:D Trapdcode's out. CC doesn't have a use layer/image option.
Option 1) Simulate>CC Particle World or CC Particle System II:
OK, drag you custom Particle into a comp the size you working on, say the particle is a psd 128x128, drag it into a standard ntsc comp, 720x480 (use your preferred comp size. Make sure it's in the middle of the comp, centered.
Now in the Project Window, drag Comp 1 onto the "Create a New Composition" button (between the folder and garbage can buttons). Now in Comp 2, select the layer Comp 1, and apply CC Particle World, or CC Particle System ll, and use these setting:
Particle> Textured Square
Death Size> increase to whatever it takes to seethe whole particle, 2 for my 128x128 particle in comp1.
You should be good to go.
Option 2) On a new Soild (comp size), Simulate> Foam
And Drag your particle into the comp, turn the eyeball off. Then setting:
Foam>Rendering>Bubble Texture>User Defined and Bubble Texture Layer>Choose your Particle (eyeball off).
I like foam a nifty particle generator especially for floating things.
Option 3) Click on Dan's head and scroll down to "Build Your Own 3D Particle Generator". It's AE 3D so you can fly a camera around, and use your own psds. Just sub in your psds for Dan's.
Dan's generator is waaaay cool and flexible once you get the hang of it. Setting up sliders in a Null and linking the factors, like Gravity, to sliders can make for quick changes, then dup that layer as many times as you want particles. This is maybe my favorite Dan tut.
Option 4) I think Particle Playground can use layers too, but it scares me.
OK, I checked it out.
Particle Playground>Layer Map>Use Layer: Choose your Particle layer.