Re: Rotoscope dancer

The quick answer is it's not quick!

I have had some experience with the (now basically defunct) program Commotion using its Roto-Splines and for this kind of effect you basically need:

1) A clean plate of some sort of the background (that you probably can produce from your footage, but not always)
2) Plenty of time!

Mainly in the past I've done Roto-Spline and paint-on type of effects for just 5 or 10 second bits of footage, so you've gotta figure that for 4 minutes, you're talking 7200 (30 x 60 x 4) frames of NTSC video, 6000 (25 x 60 x 4) frames of PAL video, or 5760 (24 x 60 x 4) frames of film. Although I've just started getting into Shake, I think the RotoShape Node is similar in function to Commotion's Roto-Splines in that you create your basic rotoshapes around your people/objects, then tweak at various keyframe points and the splines will "tween"/morph between tweaks (to make your life easier). Then you still usually have to do some fine tuning frame by frame as well, of course.

One thing Scott Squires, creator of Commotion pointed it in its documentation is sometimes to make it easier as well you can use a bunch of roto-shapes on your person or object and divide the masking into simpler areas. And for a dancer in motion your talking about a lot of arms and legs coming into view and disappearing, so yeah it's a lot of work but a good way to learn Shake/rotoscoping I would imagine.

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