Animating mask reveals - After Effects Tutorial

- [Instructor] As with most everything in After Effects, masks can be keyframed to create animated reveals and are another building block to creating engaging animations. Here, we'll take a look at some ways to animate masks inside a composition. I've got a layer here that's inside a printing press, and, as you can see, these machines are moving and I'd like to create a circle wipe of sorts to reveal on this footage. I can do that through masks. Let's go ahead and select this layer name and come over and with our Ellipse Tool, let's click and drag from the center, and, as we do, let's go ahead and Shift + Command this guy. And click and drag it until it's outside the bounds of the frame there. We'll twirl down the mask and create a brand new keyframe for the mask path and I'd like this to be the end point so let's go ahead and move this down to say, frame 20 somewhere and at frame 0, let's go ahead and switch over to our Selection Tool. We'll double click and, let's go ahead and reposition this, so we can grab this top corner here and, again, with the Shift and Command modifier keys we'll go ahead and resize this down all the way to 0%. Somewhere in there. Okay, so now from 0 to 100, we've got this mask animating on. Let's go ahead and switch this to fit up to 100% and preview that. Great, so that's a real easy way to create some animation going with masked paths. Let's go ahead and take a look at this next part. This second composition is a piece of footage where the boot, I would like for it to wipe on, just as a motivator to kind of wipe this Shopwork text onto our scene. So we can certainly select our Shopwork and create the mask on that. Let's go ahead and create a Pen Tool and let's just zoom in here a little bit and let's follow the shape of that boot and mask around this way. It's very important to set that initial keyframe, otherwise as you're moving, and making these changes, you're not going to get any animation. So, first keyframe, always very, very important. And so now here, let's go ahead and select these individual points and now I can alter just the individual points themselves. If I select both of them, I can move both of these back here. Let's go in the middle here somewhere, just try to match this timing up a little bit better and all the way back here. So we'll just rough this in, somewhere in there. We can certainly fine-tune this all the way until the very end but I want to show, what can potentially happen as you're doing your mask work on top of the text, is that now, I'm locked into this. In other words, I won't be able to maneuver my Shopwork layer anywhere else except where it currently lives. If I move it back here, now I've got to redo all that masking animation or if I resize this Shopwork text for instance, it's going to drastically alter the way that this maneuvers around with the boot. So either way, I'm kind of stuck with leaving the position of the Shopwork in its original position. There's one way around that. Instead of putting the mask on the Shopwork, let's go ahead and put it on another instance of the footage. So here in this third composition, I'm going to duplicate this footage here. Let's go ahead and go down to Duplicate, Edit + Duplicate. We'll move this up on top and as we do, let's go ahead and create a mask for the boot instead. So let's zoom in to 100%, and get it into a position where that boot is kind of stationary and here, with my Pen Tool, I'm just going to rough in a couple points to create a boot shape. Maybe something like this. And if I solo this top layer, you'll see, with my transparency grid, I've essentially created this mask to hide everything else except this boot and when you composite it on top of each other, now you have this ability now, to move around the Shopwork wherever you like, and still have that boot in place or on top. So let's go ahead and twirl this down and set our initial keyframe and using the Page Up and Page Down, what I can do is, maneuver through, frame by frame, instead of having to manually drag the current time indicator. This makes it a little bit easier in terms of being able to do the animated mask work here which is also known as rotoscoping and so, with this mask path selected, I can go through all these points and hit Command + T on the keyboard, and now I get a transform box and I'm going to take my anchor point and put it down here at the heel and let's just rotate this entire shape up like this. You get a brand new keyframe, of course, and timing is a little bit off. Let's move this keyframe over here and look for the big, big motions here. So, the heel contact is a big motion back here somewhere, that swing. Let's go ahead and take this entire mask path a little Command + T again, a little rotate around and move this guy over in this area and again, back here somewhere. Not the layer window. Let's go ahead and go back to our composition window and select our mask. We'll Command + T and rotate around and rough this guy in. Okay. We can select our individual points and move those pieces of our mask path to kind of conform to the rest of the shape. And as we get back here, let's go ahead and look for that extreme. These guys are moving, let's select them and Command + T, rotate that around and as you can see, I can select and rotate just whatever I have selected and as we push off, let's go ahead and zoom out a little bit and Command + T with those all selected again and we'll come up here somewhere. Actually, rotate and move it around. So really, really rough but you can see, we can sit here and fine-tune this all day long but the important part is that because we have this separate layer now, we have the ability to maneuver around our text. So we'll take the Shopwork bit of text we can maneuver this, we can scale it. And let's zoom this back out to 100% And there you go, let's preview that. So the boot comes across, we wipe on Shopwork. We can certainly take our mask and feather it a little bit to kind of help ease that transition. We can mask expansion shrink it a little bit. Just kind of hide the seams a little bit, there you go. So that's looking pretty good. Now let's take this shot and the previous shot with the circle wipe and combine them together and just by masking we have, a boot to reveal this Shopwork layer and we have a circle wipe to reveal getting into the letterpress shop So, by animating masks, we can create interesting reveals of logos, text or other footage, in the form of simple shapes and even more organic ones. After Effects gives us great flexibility to manipulate our masks with ease.