Tip of the Week - Rotoscoping

Rotoscoping. The technical art of tracing a frame many times. Many, many times. All of us have done it at some time or another. And if you haven't, what are you waiting for? It's a skill that should be learned, however tedious it may be. Here are some tips to help you ease the pain.

While rotoscoping moving people, I tend to use several different nodes for each part of the body. Hands, arms, legs, torso, head. Depending on your compositing package, this will make deleting or redoing any section of the person easier. Don't set keyframes on every frame, or even every 5 or 10. If you're rotoscoping a human, you'll want to match the cadence of their walk or run, so keyframe the roto on the highs or lows of their gait.

You will want to use a tool that allows you to have soft edges, so that motionblurred frames of the person will accurately be rotoed. If you're going to be rotoscoping objects, like cars, boxes, things that are usually inanimate, you can use one complete roto to cover the entire object. However, if there are extreme perspective changes, it might be better to use different roto for different parts of the object. Sometimes for objects like these, you can roto the first frame, and track the object throughout the shot duration.