The easiest way to begin is to drop any of the more than 80 Noise
Industries plug-in filters (bundled with Noise’s standalone Factory
Floor app in Xpress Pro as "Factory Tools") onto a video or still image
clip, or – a very cool Avid technique – onto any blank track above the
sequence you’d like to affect. Filter a whole sequence in one stroke!
Even better, you can build your own custom filters, or customize
existing ones, with this same OS-level technology. I’ll show you how to
add an advanced compositing tool to your Avid real-time animated blend
modes.

Rather than use the ready-made plug-in filters inside Avid Xpress Pro,
exit Xpress Pro and launch Factory Floor from your Application folder.
Select the Core Effects icon on the left side of the new window, and
press the Open Core Effects button.

In the upper left of the Factory Tools window, click on New Plug-in. In
the resulting dialog box, type a name for the effect (Composite), and
either select a category from the pop-up list, or create a new one
called Composite. This particular filter will be built on a Core Image
Unit (the default choice), and the unit itself is Gaussian Blur. Select
it from the pop-up list.

On the Renderer tab, the only change you’ll make is in the Compositing
section, to change the Blend mode from Normal to Overlay. ("Normal"
essentially does nothing; it’s never my favorite default.)

Then, on the Parameters tab, in the Numeric category, set the Initial
Value to zero. One reason I chose the Gaussian Blur unit as a starting
point is that I like the idea of being able to add a blur, just in case
any of my composites look too harsh. But most of the time, I won’t want
any blur by default.

That’s all there is to it. Save and Quit. Read on for how to use it.

Launch Avid Xpress Pro and you’ll find your filter in the Composite category that you just created.

Drag the filter onto the top of two stacked layers, and it creates a
blend with the layer below. To customize beyond the defaults, open the
Effect Editor by either choosing it from the Tools menu, or press the
shortcut button in the upper left of your Timeline window.

Feel free to experiment with different blend modes to see which looks
best to you. The results will vary entirely based on the footage you’re
using, so the "best" choice will change every time.

Here, I’m using the Soft Light blend mode, I transformed a much
stronger, summery-looking lotus into a subtle background element for
autumn leaves. Notice how the leaves blend differently with the dark
and light areas of the flower, and how the background of the lotus
scene adds much more texture to the right half of the frame, compared
to the rather flat background of the leaves. It’s a more dynamic
combination that’s also more truly blended than straight transparency
would allow.

One of the most effective ways to use blend modes is with titles. Add a
title to your sequence, and drag the Composite filter to it. It won’t
look right until you press the "Apply to Title or Matte" button in the
Effect Editor. Here’s a white title with a black border and our old
friend the Overlay blend mode. It’s quite striking how the actual color
of the text, as well as what’s showing through it, changes with the
background. It’s even more striking in motion, of course (stay tuned
for a look at this online at
www.studiomonthly.com), but you get the idea.

To finish up, save your customized variation to apply to other titles
later. Click on the Effect icon, the "plug" image in the upper right of
the Effect Editor, and drag it to any open bin where you can rename it
if you want. It’s not just filter parameters that you can save, either.
You can add keyframes before you drag the filter to your bin, and now,
whenever you apply your customized Composite filter to a title, those
keyframes will also be applied.

This is just scratching the surface. Animate the opacity of a blend,
scale the output to create two layers in one, add color- all in real
time. Set "Composite Over" in the Effect Editor to "Effect Layer" to
composite a layer on itself. Create variations of this filter in
Factory Floor to populate your Composite Effects category with the
real-time compositing that you need. You’ll be amazed what you find in
this filter as you dig a little deeper.

Tim Wilson
Sr. Product Marketing Manager
Avid Technology

Before joining Avid, Tim developed effects and titling software and ran his own video production company for 10 years.

Core Image Units are filter, effects and transition packages bundled
inside the Tiger OS itself. Their real-time performance is provided by
the graphics card that’s part of your desktop or laptop Mac. Quartz
Compositions are combinations of Core Image units. Read all about it at
www.apple.com/macosx/features/coreimage/. And
for more, including demo movies, on Avid and the bundled Noise
Industries apps, check out
www.avid.com/community/mac/. Blend modes (aka
apply modes or composite modes) give you more flexible ways of mixing
layers. Rather than simply making every pixel equally transparent as
you blend, you can choose, for example, to have dark pixels blend more
than light ones. Within a filter, blend modes might apply an effect
based on the difference between the brightness of pixels on two layers.
Blend modes produce dramatic looks, but they’re processing-intensive.
By harnessing the power of the Tiger OS and your computer’s graphics
card (GPU), Avid provides real-time compositing power.

Don’t just settle for the first thing you see when you choose a blend
mode. The Image Opacity slider at the bottom of the Effect Editor lets
you mix the results of your blend with the original layer for a much
wider range of looks.

While Avid Xpress Pro is a cross-platform app, this tutorial only applies to the Mac on Tiger.

Avid Technology
www.avid.com
One Park West
Tewksbury, MA 01876
ph. 800.949.AVID (2843)
e-mail: tim_wilson@avid.com