Join Richard Harrington for an in-depth discussion in this video Choosing and moving a target, part of After Effects Guru: Tracking and Stabilizing Footage.
Once you've successfully applied the 3D camera tracker effect, you need to work with a target. The target is where all things become connected. Now, you've seen me use targets already, but I'd like to walk you through some of the more advanced controls and the logic behind them. In this case, I have a hand-held shot walking through an alley. And there is nothing stable about this shot. The camera person seems to have some of the heaviest feet known to man. And it is not a stable shot nor is it a very smooth walk.
But I'd like to use some of the details of this scene to add elements into the shot. To do that, I need to make sure that the clip is analyzed. Now, I've already applied a 3D camera tracker effect to save you some time. As you work with the 3D camera tracker, the analysis stage is certainly the most boring. To make it a bit easier, we're hiding some of that part during the video class so you don't have to sit here and watch the machine process. But realize on a real world job there is a bit of waiting time. This is a tremendous amount of math that has to get done.
Now that we have the alley here. If I mouse over, it attempts to create targets. And essentially it's auto-detecting three points. This allows you to basically chose a target automatically. And you'll note as you get to surfaces like the walls that if it finds the right points it becomes possible to map something right to a wall, and with a click you have a target. Once the target is selected it can be moved around, and you'll note as you move it, it even changes size.
Getting smaller as it gets closer to the camera, and larger as it gets further away from the event. Now besides mousing over, you can also manually choose, by Shift+Clicking, you could attempt to choose the targets yourself. But this isn't always a useful method. In this case I guessed pretty well but sometimes it can lead to unexpected results. Besides clicking, you can also draw a lasso around a bunch of tracking points. So if I simply click outside here and lasso, it uses all of those points in that case to track the floor.
And you see that that's fairly accurate. You need at least three points to create a 3D tracker but you can use as many as you want, but once you drag, you'll see it disappears. So make you park on a good representative frame and then either auto-detect a point or lasso around several points that you want to use and let it create the target for you. To deselect a target, just click outside or in an empty area. But all in all, this is a pretty easy process.
If you get some points you don't want, you can Shift+click to remove an individual point from an existing selection. Let's zoom in here a little bit so it's easier to see. I'll hold down the spacebar to pan, and note the center of the target. When you put the cursor over the center of the target, it shows you the move arrow. This means that you can move that target around. And note how it's changing size in this case as we move through the scene in three dimensions. Larger as it gets closer on this particular plane as well as farther back.
This makes it pretty easy here to re-position the target. While you're here as well, with a right click, you might want to take advantage of identifying that this is the ground. This allows you to specify the floor of your environment, as well create an origin point for the x, y, and z axis. There we go. Now that we've got the target essentially where we want, we can do a few small refinements.
- Analyzing footage
- Using the 3D camera tracker to stabilize footage
- Choosing and moving a target
- Adding 3D text to a scene
- Tracking an object
- Applying the Warp Stabilizer VFX
- Choosing a stabilization method
- Reducing rolling shutter distortion
- Matching movement