How to attach a picture or text to a specific point in the video?


After a long pause, I will try to return to the blog. And today we will learn how to attach a picture or text to a specific point in the video.

So we need:
1. Adobe After Effects CS6 (I work in it)
2. Null object
3. Tracker – a built-in function of Adobe After Effects CS6 (it will come in handy, in Russian AE it is “Inspector” – thanks to Victor for the help, who added to my record)

So, the list is prepared. It’s time to look at all this a little more.
As screenshots for text, I will use a composition that will not take much time and will consist of a large dot moving around the screen. The composition consists of a layer (white) and a circle, the movement of which is given by two key points:

Let’s try to attach the word “Hello” to this point, which should follow our point. To do this, add a null object to the composition: Layer – New – Null object:

Why? Actually, the Zero layer is a layer that does not manifest itself in the composition in any way, but – when certain properties are applied to it, this layer will be able to control other layers. A bit confusing, but a little later, I think, you will figure it all out.

So, there is a jumping circle, there is a zero layer. It’s time to run Tracker: Window – Tracker:

An open tracker window, by the way, looks like this:

And … op-pa … The tracker generally does not understand what to track, and how – after all, he works with the finished composition, not layers! The solution is obvious: create a second composition that will use the first as a movie.

Now, finally, we can run Tracker again, and see:

Approximately all of this can be described in the following words:
Track camera – track camera movement
Track motion
Warp stabilizer – smooth out fluctuations
Stabilize motion – stabilize motion

And the possibilities of checkboxes:
Position – track movement
Rotation – track rotation
Scale – track scaling

We will consider the rest a bit later 🙂
Let me remind you, we need to track the movement. Click on: track motion, and check the Position + Rotation checkboxes. Immediately after that, two windows appeared in the composition field (highlighted in red on the screen):

Each of the windows is aimed at highlighting the area that needs to be tracked. Due to the fact that we will use our tracking to the zero object, it is possible to track not exactly the point we need, but something close. In my case, these will be the borders of the circle (see screen a little higher)

After you have chosen the points you want to track, click on the button: Analize Forfard and wait 🙂

After some time (it all depends on the complexity of the tracked composition), you will get something like this:

where each of the squares is a key point. We apply the analysis by clicking the Apply button in the Tracker window.
Then everything is quite simple – using the zero layer (let me remind you, this layer already knows how it needs to move) we attach the text to it. Add a text layer:
Layer – New – Text

and write any word. In my case, this is the word “Hello!”:

We place it in the place we need, and after that we apply the interconnection of layers to it:

thus, the text is clearly attached to the null object. Actually … that’s all 🙂

You can see the finished example below (a beer mug is hidden behind the emoticon):

By the way, as source video, the video was taken with channel of my son 🙂 Subscribe, like – he will be pleased!

And of course, in case of questions – write to the mail: