Join Lee Lanier for an in-depth discussion in this video Adding artwork and renders, part of VFX Techniques: Crowd Replication with After Effects.
There is no limit to the number of trackers you can add to a layer, at the same time there's no limit to the number of layers you can apply the tracking data to. We're going to try that in this video. First thing I'll do is put another solar panel right here, and that will require additional tracker. I'm going to use the same render as before. I'm going to go to the SolarPanels and drag that back down and make that a new layer on top. There's another iteration of the panels. Now I only want one little section of this panel, so I'm going to cut it out with the mask again.
I'll go up to the Pen tool, and draw a mask. This time I want to draw one just to cut out the leftmost panel, so I'm trying to make it nice and neat on this right edge. You can adjust these points afterwards just by click-dragging them. So there's a new panel cutout by itself. I'm going to track it to this stand over here. So, I want to move it over first to get into a good start position on frame 0. I'll do that by moving the anchor points, I can just do it right here.
I'll just slide it right over. So, it looks like a good place to start. Now I'm ready to add a new tracker. I'll pick Stabilize once again, go to Animation > Track Motion. This will be Tracker 3. Once again, we'll Transform track, so Tracker 3 has its own track point. I want the left stand over here. I'll move that into the correct location, and I'll move the track point into position. I like this little L shape down here at the bottom, nice contrast. See, I'll put it into the elbow right there.
Now remember, before we apply the tracker, it will probably be good to move the anchor points of the new layer. So let me go back to the Composition, back to the SolarPanels, the top layer, and I'll be sure to move the anchor points to the same position. Now I'll probably need to reduce the Opacity so I can see through that, and there it goes into the correct location. Return the Opacity to a high number, now I can return to the tracker. Now if you don't see the tracker, one trick is to go to Motion Source over here, and change it to a layer that has a tracker, in this case Stabilize, make sure the Current Tracker is listed and then you can analyze. And there's the motion path.
Go back to the Tracker and make sure of the correct Target, Edit Target, select to the top SolarPanels layer, and then Apply, X and Y. Quickly scrub in the Composition View just to make sure it's tracking, which it is. Now this panel is much brighter and more saturated, so what I can do is steal the effects from the previous SolarPanels layer, so I'll pick that layer, go to Effects, Shift-select the Effects, Copy those, and then Paste them onto the top layer.
Now, since this layer is in the sun, I think I might as well go and brighten it up a bit, looks a little bit too dark. I can do that just by adjusting the Curve just give it a little bit more contrast. So it looks like they're more in the same space now. Now certainly I get quite a few layers here, so I'm going to rename a few of these just to keep organized. You can rename any layer by right mouse clicking. I'm going to Rename, so Top one I will call PanelLeft, next one PanelRight, the Top Tubes I'll call TubeHighlight, and then Tubes on the lowest one.
We need to keep organized, this will be important, when we have more and more layers as we go. I also mentioned you can apply Tracking Data to multiple layers, so we can reuse some old tracking data to some brand new image sequence. So let's do that, I'm going to bring in a new render of a bunch of banners. So File > Import > File. I'm going to the Renders Folder once again, but then go into Banners. I'll select the first Banners file, and Open that. I'll drop that on top, and that's a bunch of banners that hang overhead.
Now to reuse some of the tracking data, I'll figure out what to tracker first, and I think because the Banners are roughly in the same level as the panels, so I can use the Right Hand Tracking Data from this stand over here. Now first thing I might want to do, though, is put the banners in the right place here, in front of this panel, so they should probably be below, there we go, now they're on the correct place. In any case if I'm going to use the Tracking Data from this Right Stand, I need to make sure the banner's anchor point is in the correct place. So I'm want to hide the panels temporarily, select the Banner layer and then move its Anchor Points back to this mark that we used previously, which is this V shape right here.
Then go back down to the Tracker, retrieve it, so again, Motion Source, Stabilize, I need to switch it back to Tracker 2, which matches that Track Point, then Edit the Target, pick a new target, which will now be Banners, click OK, and then Apply, X and Y. A quick scrub shows the banners are moving. Now there is one problem with this, the banners would render with the same camera in Maya as the Tubes. If you remember, the Tubes had a bit of a slide, we had to animate the anchor point, so we can look at that anchor point animation on the Tubes, and see what's going on.
In particular let's pay attentions to the Y, so on the first frame the Anchor Point for that is 291 in the Y. The Last Frame, the Anchor Point in the Y is 297, so it's a difference of six pixels. What we'll do is go ahead and animate the anchor point of the Banners also. I'll go back to the first frame and go ahead and click the Time icon beside the anchor points to start the animation process on that. Now before we get too far, we are going to decide if we like where the banners are, either too high or too low. I think, in fact, I might raise them up a bit, so I we'll try 938, 385, so raise them up.
Now also, move them a little bit in the X direction too, this makes them look that they are more centered, as opposed to the default location. So if you imagine you draw a straight line from this banner edges down, these kind of meet the corners of this raiser. Now you can choose a different location, I just feel this looks better if they're a little bit left or right, it definitely gives you a different look. So, in this situation, 938, 385 looks good. So that's the First Frame, let's go to Last Frame now.
Keep in mind that Y Offset we talked about is 6 pixels, so let's take care of that first. So, if the first frame it's at 385 in Y, let's make the last frame 391, that's 6 pixels different, which is the same as the Tubes. Now, because we changed the X also, we have to think about that. Now, one thing occasionally you have to do, which we'll do in this situation is just eyeball it. Let's say the banner starts here on the first frame, again, draw an imaginary line that goes down from the edge of the banner, down to the back corner.
If we go to the last frame, you could see that it doesn't quite line up like it used to at that back corner. So therefore, you can adjust in the X, this will take some experimentation. In this situation, though, I put in 967 here for the X so that the first and last frames have a better match. So, here's the first frame, draw a line down from the edge of the banner, roughly around here, go to last frame, draw a line down roughly the same position. So we didn't ruin our tracking data, we simply offset it, for several reasons.
One, we adjusted the height of the banners, two, we fended a little bit of that Y slide that we saw with the tubes, where it was kind of dipping downwards, and then three, made a choice to move the banners that are more centered over the podium. That required a little eyeballing to line it up to the corners. We see how we can apply tracking data to multiple layers and also how we can add as many trackers as we need to, to any particular layer. You don't always get a perfect tracking result when you apply tracking data, so occasionally you'll have to do a little manual animation.
- Setting up your project
- Removing camera jitter
- Motion tracking CG renders
- Creating light effects
- Keying with Keylight
- Solving bad matte edges
- Rotoscoping green screen footage
- Color grading to match elements
- Relighting the scene