I'm obviously new to After Effects, and I'm using CS3 (I've had the video production bundle for a while but have been using Final Cut Suite--it's a long story) on Windows 7.
Anyway, I'm trying to make a person's head explode using After Effects and Premiere and then during the explosion have small colored balls come out and shoot toward the camera. I am using a stock explosion, which actually looks pretty good. I've color-keyed the head out. I am trying to use the Particle World plug-in, but maybe I shouldn't be.
My question is: if I create a colored ball in Photoshop, can I use it as the particle in a particle generator? Because the particles are supposed to stop being generated after two seconds (because it's an explosion), I figured out how to stop the generation of the particles but how do I make sure that there are no balls "floating" when the timeline is finished and that each of them goes out of the frame before disappearing?
I hope this makes sense...
You can create custom shatter maps to control the shape of the particles in Shatter. You can shatter a layer with an alpha channel (like the actors head), and you can control the way a layer shatters using a gradient, so the Answer is YES. There are a bunch of tutorials on creating shatter maps in AE. Try a Google search and pick any of the first two or three that pop up. You'll get an idea of how the Shatter effect is controlled, then you can apply the techniques to the actors head.
You'll obviously need to create a missing head segment of the video, but that's another problem. You'd start with Rotoscoping.
I hope that helps.
Here's a Google search with some good places to start. Pick one that looks interesting.