You know the setting, an empty room. Then something prompts dust to fall from the ceiling. Most of it falls straight down, but a little bit lands on something… something you can’t see, but you can just make out the shape of a figure. And then… and then…. argh!
This is a fun technique to try, it’s seen often in movies with ghosts or invisible figures. I know I’ve seen it in Paranormal Activity 3 and I’m fairly certain it’s also in Hollow Man and the latest Invisible Man. We’re going to use Levels and Turbuluent Noise (or Fractal Noise) to highlight an animated figure. I used Mixamo to create and animate in the figure, but I could easily have filled someone instead. Then using CC Particle Systems II, we use the character’s alpha channel to generate the particles and have them float upwards. Finally, we time reverse the entire comp to have the dust fall down instead. All in in Adobe After Effects.