Compositing techniques in After Effects – The Rigid Mask Tracker

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In today’s post, Jeff Sengstack will talk about compositing techniques in Adobe After Effects and more specifically about the Rigid Mask Tracker.

Note: make sure you watch the video tutorial Jeff has prepared for you!


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Let’s start!

I’m going to put a mask on this child here and I’m going to cut it and make little bit more of an exact thing like what I’ve done with the other one. I could actually click several times here around and right click so. I could have turn on a little Bezier to make it smoother but we’re just doing that for the time being and I’m going to soften the edge anyways, so it won’t be so obvious that it’s an odd looking thing.

My bad, with the mask selected, that’s important. I did it last time but the mask acted like this. That’s what I wanted to do. But you got the tracker, that’s going to be the option right here which is called the rigid mask tracker. I don’t know why I forgot that but here you go and let’s see here.

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With that mask selected, sorry I didn’t the last time. The only option here would be to do a rigid mask tracking, that’s what it’s called. And you can choose various ways to track the mask. I wanted to do a position scale rotation. They work better not just for positioning scale but there’s no option for position and scale only. So that’s position scale and rotation.

Now if I click this and go forward, it will track that young man pretty slowly but what’s going to happen is that this thing will tilt as the boy tilts its bike and as he comes toward me, the mask will expand.

tilt selected

The points won’t change their relative positioning but the mask will get bigger as the child comes towards us, because he’s getting closer to the camera. And gradually you’re going to be making a whole bunch of cute frames here and it will be within the mask, which is what went wrong last time. I only stopped here because it will take a long time to do all the thing.

Now if you open this up, the key frame is in the mask, which is what I was trying to do last time when I blew it so sorry about that. You need to do a rigid mask tracker when you’re doing this. That’s the cool thing. So now we followed him for that little distance, anyways so you could see how this works.

And now I want to apply some effects, not to him, but to everybody else. So you can go to mask here and instead of having it like an add, I can make it be a subtract. I could click inverted. Either one works, they both work the same way. So now we’re protecting everything in the scene but the child, which seems terrible but we are going to fix this in a second.

What I want to do is get let’s say, a blur so we’ll get to Gaussian blur, why not. I get out of the layer. I’m going to blur all these things in the background.


So I get repeat edge pixels and blur everything like that, which will be sufficient, I think. But let’s also darken it a bit. So I’m going to get the curves and apply curves to this as well. Drag it over the video clip. I could pull things down the middle and just make things darker. It will be sufficient for our purposes.

Now what I can do now is I could mask the boy and I would have put a layer above everything and then I would have put these effects, the curves, and the blur on the layer below it so the boy stays sharp and the second layer below was blurred, that kind of stuff.

But here I can do within one layer. The way I do that is place a rigid effects down here, not up here, but down here. This is where the composting the options will be. Go to them one at a time, compositing options, click on the plus to add the mask, automatically apply it to the boy. That’s still dark, right? That’s because the other one is not applied yet.

Compositing options to the curves, now you see that the boy is bright and sunny and everybody else is dark. And I can go back and do to the mask and we can soften the edges a bit. We can feather it. So it’s not harsh around the edges. My drawing is not going to be, obviously like a direct expand the mask a little bit. So it comes a little bit more of him. And now it will follow him. I’ll turn off the mask visibility by clicking right there. And now the mask will follow him like so.


Thank you for watching this video. My name is Jeff Sengstack, and Adobe certified expert and the lead instructor here at If you want to watch this entire video lesson as well as other live classes and After Effects crash courses, then I invite you to check out the Blue FX After Effects Academy. Just click the link below this video to find out what we’ve prepared for you in the After Effects Academy.

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Remus Hosu

Remus Hosu

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