Game Development Reference
The last comp in this project, EKG, shows another use of the
Vegas effect. Here, I use it to create an EKG, or electrocardiogram.
I realize that if you are a physician, you'll probably know it's an
obvious hoax. But. if you're creating a movie, and need to show
someone's lifeline in the background, this is a good trick to keep
in mind. It's just the Vegas effect with a jagged mask, and is only
one long segment (Fig. 9.51).
Figure 9.51 The Vegas effect can
also create an EKG effect. Notice
the special guest appearance by
the Grid effect, discussed earlier
in this chapter.
The Write-on Effect
The Write-on effect creates animated strokes. The purpose
of this effect, more or less, is to create animated signatures.
Many users have discarded this effect in favor of the more
powerful painting engine in After Effects. However, the paint-
ing engine in After Effects doesn't let you paint to reveal the
original layer. This is a significant advantage of the Write-on
effect that we'll use to create the ever-popular growing vines
effect a little later on.
For now, open up the Write-on.aep project from the Chapter 9
folder, and go to the Write-on Start comp. Select the black solid
layer and apply the Write-on effect to it. Again, as with Stroke and
Vegas, the default Brush Size value of 2 doesn't do us any good
(were these effects designed for hobbits?). Bump that up to a
value that will allow you to see it. Many of the properties here are
identical to what we've seen in other effects in this chapter.
It's when you start animating the Brush Position that you start
to see the magic of this effect. As you animate the position of the
brush, it maintains a line, allowing you to create an animated sig-
nature or other line drawings (Fig. 9.52).
An Easier Way to
If you're going to
have the Write-on
something complex, like a
signature, it's probably a
better idea to use another
method than manual
animation of the Brush
Position property. You
could use Motion Sketch
to capture complex motion
quickly, and then connect
the keyframes created by
it to the Brush Position
property in the Write-on
effect with an expression.