motion blur for rotoscoping?

Yesterday I experimented with a basic rotoscope test, mimicking the ‘jedi’s pencil’ video clip. The one thing that got me stuck was, working with live-action frames, I had some motion blur on the original footage I couldn’t easily hide, short of grossly stretching the rotoscoped line (which worked but gave a cheap-cam effect.)
In the jedi pencil clip the guy mentions he used a motion blur, but I can’t seem to figure out how he configured it.
Any tips?
(Original video (without blur-cover) here: box.net/shared/r264lm2suv )

Place the motion blur layer on top of the layers you want to be affected. Then sets its aperture parameter to be something bigger than 0f (it is the amount of time of the aperture of the shutter if you were using a photo camera) You can play also with the interpolation type and set it to lineal to achieve the standard effect.

A value of 0.1 - 0.2 seconds is enough to make it noticeable. Bigger values produce excessive blur effect.

Very well rotoscoped indeed!

-G

Ahah! Thank you!