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Tracking Strokes
As mentioned before, paint strokes include their own editable properties. Not only can you edit or transform
their shapes, which isnt so often necessary, you can connect the motion tracker directly to a paint stroke.
Cases come up all the time where artists can save themselves a ton of work by attaching paint strokes to
motion-tracked objects. However, to do so requires use not only of the tracker, which is covered in the next
chapter, but also of basic expressions. Thus this topic is fully covered in Chapter 10, Expressions, as an
excellent example of a simple use of expressions and offsets.
Wire Removal
Wire removal and rig removal are two terms regularly bandied about in the visual effects industry. Generally
speaking, wire removal means painting out a wire on a blue-screen shot, a wire usually used to suspend an
actor in mid-air. Rig removal, meanwhile, is even less glamorous: Its just garbage masking any equipment
that showed up in frame.
Some rotoscoping applications have dedicated wire-removal tools, but in After Effects, youre on your own.
However, wire removal need not be a painstaking process in After Effects simply because theres no dedicated
tool for it. There are several approaches that could conceivably work; if the ends of the wire are trackable, you
can track position and rotation and apply these to a null, which would be the parent of a masked element to
replace the wire. This specific instance, with an example, is demonstrated in the following chapter.
Rig removal is often aided by tracking motion, because rigs themselves dont move, the camera does. The key
is to make a shape that mattes out the rig, then apply that as a track matte to the foreground footage and track
the whole matte. See Chapter 8, Effective Motion Tracking.
Plate Restoration via Cloning
This is as nitty-gritty as rotoscoping gets. For various reasons, even on the highest budget visual effects film,
the shooting and transfer process introduces flaws visible on a frame-by-frame basis: Dust and scratches make
their way onto the pristine master.
Most of these flaws, alas, will be corrected only via frame-by-frame cloning, sometimes known as dust bust-
ing. Large visual effects houses have teams dedicated to this work, a motley crew of mostly entry-level folks
who listen to a lot of audio books. I mention it separately not because it requires a different approach than is
outlined here, but because you might not be aware that such a job exists, let alone that it could be an entry-level
job at a major facility. If youre in one of the main visual effects hubs (Los Angeles, San Francisco, London,
and so on) this of course is the type of work that increasingly is being off-shored to cheaper markets.
One final note about this work: Despite its apparent tedium, its not all done via a monolithic approach; there
really is some art to it. In some cases, cloning with an offset will work. In other cases, youre better off masking
out a part of the source to reveal the footage you want to replace by placing that clean version behind it. Never
check out completely, because you never know when you might devise a better way to approach a problem,
and the problem-solvers are the ones who get the promotions.
Conclusion
And so, like rain, into every effects artists life a little rotoscoping must fall. The tools outlined here are mostly
sufficient for the type of rotoscoping work that compositors will have to do. Dedicated rotoscope artists would
likely choose software other than After Effects to ply their trade, or perhaps employ Silhouette as an After
Effects plug-in. As long as rotoscoping isnt your stock in trade, however, the After Effects tools will usually
allow you to complete the shot without having to look for other software.
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The next chapter completes the picture by adding motion tracking to your areas of expertise. As mentioned,
motion tracking plus rotoscoping can equal a shortcut around tedious tasks.

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