Join Jeff Foster for an in-depth discussion in this video Basics of match-moving, part of After Effects: Advanced Compositing Tracking and Roto Techniques.
Okay, now we have our patches all tracked in there. And you can see they patch up the tape holes pretty well. They're not perfect, but it's good enough that we can pull a decent Key and not have them distract from it. So, I've already done that for you in the comp. It's the Christmas Window Home comp, you can open that up. And you can turn on the Keylight, which reveals our background. And you see our background plate is just a static JPEG here. And in this case, he's going to be the focus, our snowman.
He's going to be the star of the show. So, I want my foreground to match my background, which is that warm, incandescent Christmas lights. So, I've already applied some levels here. And you can go in there and see exactly which settings I've made on the different channels to closely match this. So, now my lighting of my foreground plate matches. We just have to match our motion. Now, I'm going to track part of the foreground, just to match my background to the foreground as far as camera motion is concerned.
And what we'll do is then we have to physically match move, and that is a process of actually moving our anchor points. So, that we actually have a believable emotion with the camera. And that's all very subjective. And you're going to see, that process takes a little bit of time. But first let's get our tracking going here. I've got my foreground selected, and instead of double-clicking it which only opens up this other comp we've done here. I've just got, selected once and I come over here to my Tracker window and hit Track Motion.
And now it opens it up here for us to find a track point, and I'm going to just move this up here to this little piece of the chandelier here. And center that in there cuz I need some contrasting spot there, and make sure that I'm at frame zero here and then hit my Analyze Forward. Then we'll come back and finish the track. Okay, so we can see the difference of the motion in here, and it's not a real smooth curve, even though the dolly looks pretty smooth.
We do have some motion here of the camera tilting and moving on the dolly. So, that's really important to note that, because when we apply that to our background, we'll see that it does kind of tie the two together, at least as far as that's concerned. So, after edit our target and we want to select our background here, which is this JPEG and click OK, and then apply x and y and now we're back to our comp here. We can see that the tracker has put some points in here, and we can click that off.
And then we can look and see what it did to our background here, if we twirl down our Transform. We've got a Key frame on every single frame of this which is our tracking position. Let's take a look at the motion. And even though the camera motion looks like it's moving our background okay. We still don't feel it's that believable because it's not really changing in its scale or in proportion to the window. The background is just staying too static, and we need it to kind of move up and over in frame so that it feels. And that's where we have to do this subjective match moving. Well, the first thing we need to do is find out at what point does it start making most of the moves.
So, I use the scrubber here after I've done a RAM preview, so I can kind of see that easily. And it looks like it kind of takes off here, starts taking off here. So, I know I'm going to have to make some motion somewhere in here, and so I'm going to make a little marker here. Let's click marker, and drag it over. And then, somewhere over in here, it starts to slow down. It doesn't really slow down entirely till the end. But it does most of its move before it eases in here toward the end. So, somewhere in here.
I"ll probably stop more of the actual match moving, so I'll move that here and then just let the tracker take it from that point. So, the match moves I want to make on this layer. Will be, actually it's position, but I'm not going to change position because my position is already used up with all my track points. What I can change is my scale and my anchor point. So, my anchor point is the point where if you just click and drag that, you see that it moves it around in there. The anchor point is the actually centering of your frame. So, I'm going to undo that, of course.
I will click my stopwatch for anchor point and in scale, because I'm going to leave it at that as the starting point. And then when I come down here, I kind of note that, well, the camera is moving this way and is kind of zooming in a bit. It's coming in on the background. And it's kind of moving up in frame. And if we were to really look out there, the, the snowman would move off to our left. So, I'm going to just generalize a position, at this point.
And I'm going to bring up the scale, a little bit. Then I want to make the x settings on the anchor point, I want to move those to the right, to push the layer to the left some. And then I'm going to take the y settings and move those up, so it comes up in frame just a little bit. And that's just a first step generalization, for making my match move. So, I can take a look here and see how much am I moving it, too much in one direction? Am I not making it smooth enough? And one thing I'm going to do is actually do an ease out of this setting here. So I right-click on both of those Key Frames, Key Frame Assistant, Easy Ease Out, that will make that a much smoother transition, so it doesn't just take off. And then here I will ease in, so I'll select both of those. Right-click and Easy Ease In.
So, that means it won't just have a giant stop either. So, now I can kind of scrub through, see how this works, and if its close enough. So, I just have to kind of go back and forth. And tweak this a bit. Maybe scale this a bit. And play with it a bit. And try to get that matched in there, so that it looks good. And this, takes a little bit of time to do this, especially when you have kind of a start and a stop point.
We don't have key points along the way to really check in on. So, we just have to kind of guess, okay, where's the camera pointing? What is it focusing on? And then we move from there. Then in our next movie we'll take this to the next step and we'll start adding in some other believable elements, such as some snow and things to really kind of pull this together. But in the meantime, go ahead and play with this, and see if you can move your background anchor points and your scale, to kind of match what you feel this should be.
And then, if you have to, go to the completed one. And kind of look and see what was done with the final. And see how close you are in your guesstimation of those. And we'll come back to the next movie.
- Roto-painting techniques with a Wacom tablet
- Keying both green and blue in a composite
- Masking to isolate parts of an object to key
- Using multiple layers and roto on a bad green-screen shot
- Motion tracking and match-moving
- Matte painting and moving background/foreground plates
- Lighting techniques in post