The project is long past. I just didn't put it in. But the DVD hasn't come out yet. So I may try to go back and add it. Still trying to figure out the best way to do it.
The technique works pretty well.... I've talked to some guys over at cgtalk.com and man, you can get really crazy doing 3D. This particular example is the "easy" way.
I've been using Maya for about a year, and hadn't even seen some of the tools for the "complicated" way!
That is a great link! I have the personal learning edition of Maya right now. I figured I should get good at it before I drop the cash for the real version. As soon as I get it, I'm gonna go back and do that.
AE particle systems should be able to pull this off. A 3rd party 3D particle system plug-in would be better, I prefer Trapcode Particular.
The key to pulling this off would be to use _lots_ of smaller particles, and apply a blur. Then set the layer to 10% transparency and experiment with transfer modes.
If you play with this I bet you could fool em, and _much_ cheaper then buying Maya.
I would always go for the practical solution. I think 3D breath looks fake, so I would shoot it, lit from the bottom or the side, against black material in a meat locker and then composite it into the frame. You can actually say the right lines of dialogue in the freezing cold, and so it automatically looks right. They did it like this in Titanic (only a few shots were digital).