Game Development Reference
Figure 5.15 The blend modes
offered in the Blend effect.
The Calculations effect (coming up next) is much more power-
ful, and does both of these blend mode tricks, but it does them
much better. We'll save our look at these features for our upcom-
ing coverage of the Calculations effect. For all your purposes, you
probably should be using the Calculations effect instead of the
Blend effect anyway.
The Calculations Effect
The Calculations effect is another from the range in the
Photoshop, and it's perhaps the most powerful one in this chap-
ter. It primarily allows you to blend a channel (or the entire com-
posite) of the layer you've applied it to with a channel (or the
entire composite) of any other layer in the same composition. You
can also composite them using any of After Effects blend modes,
and can animate the changes between them.
Open the Calculations.aep project from the Chapter 5 folder
of the exercise fi les. It's important to note that the comp in this
project contains three layers—two Artbeats video clips and
some more medieval art from my friend, Will Kindrick. Note
especially that the knight layer separates the two Artbeats clips
(Figs. 5.16-5.19 ).
Select the layer CED113.mov and apply the Calculations effect
to it. At fi rst, these options may seem a little baffl ing. But they're
Figure 5.16 The layer stack
in the Timeline panel in the