Join Maxim Jago for an in-depth discussion in this video Animating garbage mattes, part of Compositing with Premiere Pro CS5.5.
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Garbage Mattes really come into their own when they're animated. And though you may want to use something like an Advanced Track Matte or even throw work into After Effects to do really advanced compositing via rotoscoping where you're painting to define transparency, you can use Garbage Mattes with animation to achieve some really advanced effects. And here, for example though, a simple example of that. I've put an 8-point Garbage Matte on this layer, and I've got a Radial shadow on it.
So, it's given me some edging as well, and what I'm going to do is animate to follow the movement as our ball thrower moves off the screen. You see the camera does a fast pan. And what I want to do is clear him off the screen so that we see the ball get hit and then, here we go, a bat's man is off. So, what I'm going to do is just scale this up a little bit and open up my image a little bit and expand out my 8-point Garbage Matte. There's a little word of warning here, as well, I suppose.
That, of course, the more points on your Garbage Matte, the more animation you have to do. So, try to go for the minimum number and only go for something like the 16-point Garbage Matte if you really, really need it. So, I'm going to zoom out a little bit to 25%, so I can see all of the points on my Garbage Matte. And now, it's simply a question of just zooming in properly on the Timeline so I've got only the bit that I need to work on. This is going to give me a smoother range to follow through with my key frames.
I'm going to turn on Key Framing for all of the nodes on my Garbage Matte. And then, having done that, I'm creating automatically a key frame at the very beginning of my shot. And I'm just going to start dragging through there, I want to start moving this up so I can see his hand come back. Looking good, let's have a little bit more. Maybe I can come back a little bit with the top here.
Come in with this knee. And the beauty is that once you've turned on animation for your matte, you really just need to find the points you want, and move them at appropriate moments in time. So, that's looking pretty good. I'll do this kind of fast, but (UNKNOWN) you'd probably spend a bit more time on it. Okay. Now, he's heading off, so let's pull this matte in. And you can see how working with more than 8 nodes, it'd really be pretty time consuming.
And I guess it depends on if you're paid by the hour. (LAUGH) Let's just pull this back, and now I'm taking these right away out of the picture, because my subject is gone from the picture. And as I'm making these adjustments, you can see the, oh, that's me adjusting the Bezier handle. Let's pull that back. You can see the motion paths being created. So, as I drag through this, you should be able to see each of those nodes following their own motion path. Now, if you've worked in the Effect Controls panel before and you're used to working with a Bezier handles for things like positioning. This is where it can come in pretty useful because the Bezier handles will give you a curved adjustment which is more noticeable where there's motion involved.
If I set the spatial interpretation to Bezier, then I can, in fact, even if I set it to Auto Bezier, so it's a little bit smoother. You'll see if you zoom in, and track it, and follow it, you get a smoother curve through space. It may not matter to you but this is where it can begin to make a difference. Okay. So now, if I click away from my effects and maybe go Full Screen, set this back to Fit, let's take a look at what we have.
It's pretty fast, but the result is exactly what we're looking for. Our subject disappears off the screen. And of course, I'm faking this a little bit, because in reality, the kid in the background that is throwing his own ball. But we could easily do an equivalent effect on the Background layer and have these two just floating in space playing a game of baseball together in, in amongst the stars. And this is the kind of detail work, even though this is only a few frames into the shot.
We're not even, how far are we, we're about a second, not even a second and a half into the shot. But this kind of detail work is what you're going to be doing when you're working on advanced composites using Premiere Pro.
- Introducing Premiere Pro: the compositing program
- Understanding transparency and alpha channels
- Adjusting opacity
- Working with garbage mattes
- Luma keys and chroma keys
- The Ultra Keyer
- Nesting sequences
- Understanding and using blend modes
- Creating track mattes