Game Development Reference
The Box Blur Effect
The Box Blur effect is perhaps the most advanced of the stan-
dard blur effects (e.g., Fast Blur and Gaussian Blur). It appears
that this effect gets its name from its default boxy results. But as
we'll see, this effect can actually achieve smoother results than
Fast Blur or Gaussian Blur.
Open the Box Blur.aep project from the Chapter 4 folder of the
exercise fi les. This project contains a comp with a simple shape
layer that will help us to see what's really happening with the Box
Blur effect. Then we'll look at another example of the Box Blur
effect using a comp in this project that contains a still image.
First, go to the shape layer comp and apply the Box Blur effect to
the shape layer (Fig. 4.9).
Figure 4.9 The shape layer in the
Box Blur.aep project. This simple
example will help us to see what
the Box Blur effect is doing.
The default settings of the Box Blur effect don't do very much.
Increase the amount of blur by increasing the Blur Radius param-
eter. If you take this value to small amounts (<5), the blur will
seem somewhat similar to a generic blur. Take the Blur Radius
value to 50 to see the boxiness of this blur effect (Fig. 4.10).
This type of boxy blur can create interesting results with
motion graphics. But what if you wanted a smoother blur? One
of the paradoxes of the Box Blur effect is that it can create blurs
that are both boxier and smoother than standard blur effects
such as Fast Blur and Gaussian Blur. This is all thanks to the
Iterations parameter, which determines how many copies of this
blur is applied to the layer. So, if we use an Iterations value of 3,
it would be like duplicating the effect three times. This creates a
very smooth blur (Fig. 4.11 ).