Game Development Reference
THE BLUR & SHARPEN EFFECTS
The effects in the Blur & Sharpen category all soften (blur) an
image or make it more crisp and detailed (sharpen). There is a lit-
tle skew in the balance here, as only 2 of the 13 effects in this cat-
egory deal with sharpening (and only one of those is any good).
The remainder all apply some degree of blur.
Blurring is useful in After Effects for a whole host of reasons. It
can soften an image or parts of an image to create a focal point
for the viewer. Blurs are frequently used with motion graphics
to create wispy or glowing elements. Blurring is also commonly
used with particle effects such as Particle Playground or Radio
Waves, when creating objects like snowfl akes or glowing sparkles.
Blur can be used in compositing, as when you're trying to com-
posite something very pristine (such as objects rendered from a
3D program) with something a little more rough (like live action
footage). Blurs (particularly Motion Blur and the Directional Blur
effects) can be used to simulate and suggest motion. Blurs can
also be used to smooth out textures that are to be used as maps
to control effect properties. And these are only a few of the many
things that blurs can be used for. Because there is such a diversity
of purpose, it makes sense that there are 11 different blur effects
in After Effects. No matter what you use After Effects for, chances
are being a master of these blur effects will help.
The Bilateral Blur Effect
The Bilateral Blur effect, introduced in After Effects CS4, is a
unique blurring effect. It is similar to the Smart Blur effect that
has been in After Effects for a while. Both blur effects attempt to
keep edges crisp while blurring surface details, which is also simi-
lar to the way that the Surface Blur fi lter works in Photoshop. But
the Bilateral Blur effect allows a slight amount of edge blur, which
creates a real dreamy appearance that still appears natural. Like
the Smart Blur effect, Bilateral Blur can also be used to smooth
out compression artifacts and other surfaces while keeping edges
sharp. Also, contrary to its intimidating name, it's a very simple
effect to use and master.