Rotoscoping is not only the art of making a subject look animated, but it is also responsible for greenscreen effects (Forrest Gump) and those doppelganger effects in some films (Eddie Murphy's Nutty Professor).
Luckily for the filmmaker on the budget, rotoscoping is alot easier and cheaper nowadays. The effect is easily achievable on a computer with high-end motion graphics software. Adobe After Effects is optimal, but you may want to try out some open-source software as well.
When shooting, keep these steps in mind:
- You should plan for rotoscoping prior to reaching post-production stage, ideally, in preproduction.
- Shoot your live-action in a neutral and uninteresting location, such as a soundstage. This will help maintain a clean rotoscoping without looking cluttered.
- Pay close attention to light and shadow during the shoot. You don't want your subjects looking too 2-d!
- Rotoscope only works if your actors actually act. Rotoscoping maintains a human element to what appears to be living 2-d art.
- Use a vector technique (such as the infamous "pen" tool) to draw around your characters or objects. Some programs can trace a subject automatically, but always check the accuracy first for a professional look.
- This would be used as a matte, which you can use to onionskin (superimpose) your image to sync with the live footage. Your matte and your live footage should have the same frame rate.
- For Kanye's look, you would need to flatten the colors of your actors. Stick to a limited palatte that creates a "pop art" look.
- For the A-ha or the Charles Schawb look, draw a visible outline around the subject. Make the line as thick as you would like. Emphasize the lines, not the colors.
- In both, resist the temptation to dramatically recolor actors' clothes.
- Don't forget keyframes or rendering!
- Practice before make significant changes to your rough cut.
For more great examples of rotoscoping, check out the master: Ralph Bakshi. His films like American Pop and Lord of the Rings inspired many filmmakers.Happy Filmmaking!