by
David Nagel
Executive
Producer
dnagel@digitalmedianet.com
As one reader
pointed out to me last week, it's been a little too long since
our last look at Synthetik Studio Artist. I had promised I'd
show you a post-processing technique that allows you to vary
strokes over time. Let it never be said that Dave fails to follow
through on his promises, even if such fulfillment does take
some time. Now, this is not the same as making strokes longer
or shorter over time. I'll cover that one in a future installment
(just as soon as another reader reminds me that I'm lagging).
Instead, this technique allows you to change the actual number
of strokes that appear in your video.
Typically
in a situation involving this technique, you're going to want
to use it as an alternative to simple fading of the movie in
and out. Rather, this will let you phase the image in
and out by moving from no strokes to full strokes and back to
none. If you click on the image below, you'll see an example
of what I'm talking about. This shows a skydiver (actually a
skyboarder) jumping out of a plane and performing some aerobatics.
You'll see a white image to start with, followed by some pencil
sketch, followed by a full-color image. Please keep in mind
that compression for the Web has altered the look of the video
somewhat.
This is
not a terribly difficult technique, but, as with all things
Studio Artist, it's also not readily apparent how you can go
about doing it. If you don't already have Studio Artist but
want to follow along and see what it's all about, visit http://www.synthetik.com
to download a demo.
For this
example, I'm going to phase in two separate brush stroke types:
a pencil outline and a color fill. And, what's more, I'm going
to stagger them so that the outline appears first, with the
color filling in a bit later. I'm also going to apply a couple
of my favorite Studio Artist Image Operations, which are irrelevant
to the tutorial but make the movie look better. These are Image
Compressor and Geodesic Watershed. I'll discuss these a little
bit later on.
We're going
to work this one stroke at a time to make things simple. And,
while I'll be using two specific types of strokes for this example,
you can use this technique with any Studio Artist preset or
Paint Patches that you create yourself. In fact, I did create
these Paint Patches myself, which you can download
here and use yourself. Also, if you happened to like the
example above, you can download
my PASeq here, which will let you apply exactly the same
effects to your own movies.
Phase
in
Start by opening up Studio Artist and choosing the movie
that you plan to process as your Source Image. Don't worry about
damaging your original footage; we're not going to be doing
anything to it except using it as a source for our final output.
The original footage will be untouched.
Then open
up the Paint Action window (PASeq window), and erase what's
there. Click the Record button in the PASeq window, and then
follow these steps.
1. Click
the little arrow above your Canvas to set the Canvas to white.
(Do this even if your Canvas is already white because it needs
to be recorded in the PASeq.)
2. Choose
your preset (or custom Paint Patch), and click the Action button.
Don't worry about how long it runs. We'll be adjusting all of
this later. So go ahead and stop it whenever you'd like.
Click the Play button in your
source window
to advance to a frame that will be typical
of your movie. This will help you get your
settings just right.
Shortcut:
You can use Command-Spacebar to start an action and Spacebar
to stop it.
3. Uncheck
the Record button in the PASeq window.
4. Click
on the first frame in your PASeq timeline (the one that's colored
red). Your action will automatically redraw itself; but don't
worry about this, as we'll be modifying everything manually
so that, in the end, you'll have only the number of strokes
you want.
The first frame of each action
in your PASeq timeline has a
keyframe, indicated by the red coloration. You can set
your own keyframes or modify existing ones by
Option-clicking on the desired frame.
5. Switch
to the Paint Synthesizer and open up the palette called Path
Start. Right at the top you'll see a field labeled "Max Strokes."
Change the value to 0.
6. Now Option-click
on the first frame in your PASeq timeline. You've now set the
first and all subsequent frames to render zero strokes. Simple?
It surely is.
7. Now you
want to be thinking about how many strokes you're going to want
in the full animation and how long it should take to phase in
from zero strokes to that final number. The number of strokes
is highly dependent upon the type of strokes you're using. So
I can't really tell you that; it's a matter of taste and too
many variables. Timing is also a matter of taste, but here's
some advice. Animations in Studio Artist tend to look best at
10 frames per second. Why? When they get much higher than that,
they stop looking like graceful animations and more like noise.
This is owing to the fact that every single stroke in every
single frame looks slightly different. So try to keep your frame
rate in the 10 FPS range.
Tip:
You can change the frame rate of your animation in the Timeline
Animation palette. This will have a direct effect on how your
final processed piece looks.
This also
has a direct effect on timing. At 10 FPS, your transition should
be complete somewhere in the neighborhood of frame 20 to 30
(two or three seconds). For this example, we're using frame
25 to mark the full phase in.
So for this
example, I now want to click on frame 25 in the PASeq timeline
and enter in the final number of strokes. Then I will Option-click
on frame 25. Studio Artist will handle everything in between
for me, adding strokes from frame 1 until it reaches the final
stroke count I've set at frame 25.
Phase
out
If you want to fade out the same way, the process is similar.
First, you're going to need to know the total length of the
piece you're going to process. If you're creating your PASeq
with the footage that you plan to use for your final render,
then Studio Artist has already given you an appropriate number
of frames in your PASeq timeline. If you're not using your footage
for this, you're going to have to do some calculating. Multiply
the length of your movie (in seconds) by 10 to get a frame count
that correlates in Studio Artist. If you are working with a
10-second piece, that's 100 frames. By default, Studio Artist's
PASeq window only gives you 20 frames to work with. You can
change this number in the Timeline Animation palette.
Note:
Extending the bar in the Timeline Animation palette gives you
a maximum of 100 frame. You can manually enter a longer number
in the frame filed.
So let's
say you're dealing with 100 frames, and you want a 25-frame
fade out. The first thing you want to do is Option-click on
frame 76. This will let Studio Artist know that you want to
maintain maximum strokes until frame 76, at which point it will
start decreasing strokes to whatever number you set at frame
100, which is your final frame.
To set the
value to 0 at frame 100, click on frame 100 in your PASeq timeline.
Then go back into the Paint Synthesizer and enter 0 in the Max
Strokes field, and then Option-click on frame 100.
You now
have a complete phase in and phase out.
So now let's
say you want to add in a second set of strokes that phases in
at a different rate from the first set. It's almost exactly
the same process, but with one exception.
First, check
the Record button in your PASeq window again; select your preset;
and click Action. When you stop it, this new action will appear
in your PASeq window right underneath your first one. Set the
first frame to zero strokes using the method outlined above.
Now I want
this second set of strokes to begin phasing in just as the first
set finishes (frame 25). So after I've set my first keyframe
at zero strokes, I'm going to add another keyframe at frame
24 just by Option-clicking on that frame in the PASeq timeline.
This tells Studio Artist to draw zero strokes from frame 1 to
frame 24.
I want my
second set of strokes to phase in after about two seconds, or
20 frames. This means I'll set my next keyframe at frame 44,
using the method explained above. To fade this out, we'll also
just use the method described above.
Additional
effects
I mentioned earlier that I'm using two additional effects
in my example for this tutorial–Image Compressor and Geodesic
Watershed. These are my two favorite Image Operations in Studio
Artist. They're called Image Operations because, unlike Paint
Patches, they do not use individual strokes. Rather they process
an image much like a Photoshop filter does.
Image Compressor
is to an image what a compressor/limiter is to audio. That is,
it restricts your image's colors to a certain range based on
the color on your Canvas. The effect is similar to saturating
an image. In fact, the Image Compressor I used for this footage
was set only to affect saturation. The image was a bit muddy
without it, so I thought it would help.
Before (top) and after using
the Image Compressor.
Geodesic
Watershed is another Image Operation, but this one makes your
image look kind of soggy. You can see the before and after images
below.
Before (top) and after using
the Geodesic Watershed effect.
Processing
your movie with PASeq
One final note: I mentioned earlier that Studio Artist animations
look their best at about 10 frames per second. But what if the
footage you're processing has a higher frame rate than 10, which
it almost certainly does? Studio Artist gives you the option
of processing movies at their native frame rate or at Studio
Artist's frame rate. To make sure you're processing at the frame
rate you want, open up the Process File Settings dialog (located
under the Movie menu), and select "Timeline Animation FPS."
That's it.
Save you PASeq for future use by selecting Action > Export
Paint Action Sequence. To test out your animation (or do the
final processing), select Movie > Process Movie File with
PASeq > To Movie. Remember, this will not overwrite your
original footage. It will create a completely new uncompressed
QuickTime file. After you name your new file, you'll see each
frame of this great technique rendered right before your eyes.
