A Guide to After Effects Masks

masks are an essential tool in after effects professionals use them in motion design and visual effects all the time learn how to start using them in your workflow with this short and easy tutorial hey this is kyle hamrick senior motion designer at school of motion today i'll cover how to create masks in after effects and show you all about their individual properties and the best ways to work with them masks are a fundamental after effects feature that allow you to cut out and combine different elements together build quick and easy transitions and are the basis of visual effects and compositing work in after effects let's take a look at what masks are and what they do how to create them the properties of masks and what each of them do working with transforming and animating masks and then i'll show you a few useful examples if you want to follow along check the link in the description and go snag the project files i'll be using in this tutorial let's get started [Music] masks in after effects allow you to determine the visibility of specific parts of a layer this is similar to features that may already be familiar if you use photoshop illustrator or other image editing apps you can isolate an object in a photo or video create a cutout make shapes or even insert your friends into their favorite music videos masks are created by drawing paths like i'm doing right here on any layer with a visual component that is anything you can create or import into after effects that you can actually see in a composition it's possible to create what are called open pads which are just kind of like a line you're drawing on the layer and those don't do anything by themselves but when you close up that path or draw a complete shape you're creating a closed path which will cut out a portion of the layer like this when you do this you're affecting what's known as the layers alpha channel which is kind of a secret invisible channel that determines the visibility of different portions of the layer depending on what you do with them this is the basis of what's called compositing when you combine different elements together to create a new cohesive image or video [Music] to create a mask you first need to select the layer you want to apply it to then grab one of the shape tools from the toolbar right up here which you can also cycle through quickly by pressing q simply click and drag here in your composition viewer and congrats you've made a mask one important note if you start using these drawing tools without a layer selected you'll be creating what's called a shape layer which i love but that's a whole other topic as you can see your mask will draw from the top left corner unless you hold command or control in which case it will draw from the center if you're drawing a rectangle or ellipse holding shift will keep all the sides equal allowing you to make perfect squares or circles many times you'll need to draw something more organic though and that's where the pen tool comes in you may recognize this tool from photoshop or illustrator and it works very much the same way here again i need to make sure i select the layer and then just click click click click to make a shape here to create rounded corners i'll click and drag while creating these points there are some variant pen tools up here for adding subtracting and modifying these path points pressing g repeatedly will cycle through these different modes shown you how to create masks now let's see how they actually work you can see i already have a mask on this layer so i'll press the m key to reveal it on the timeline the first property you'll see on the mask is the mode this determines what the mask actually does add means you're seeing only what's within the mask subtract means you're seeing everything that's not within the mask none is a useful mode for when you're working with a mask but still need to be able to see the rest of the layer these other modes really only come into play once you add multiple masks to a layer so let's try that but first here's a cool pro tip you can actually set these modes as you're drawing the mask by pressing the corresponding key before releasing your mouse click if i draw a second mask on my layer i'll make this one an ellipse notice that after effects adds a new mask right here in the timeline as mask 2. since these modes are both set to add i can see what's inside both of them if i set the mode for mask 2 to subtract now it's actually cutting away from my other mask if i set the mode to intersect now it only shows the area where these two overlap much like layers and effects here in ae the stacking order matters i'd encourage you to just grab an image draw a couple masks and explore this functionality to get more comfortable with it if you are adding multiple masks to a layer you're definitely going to want to keep them straight right you can rename any mask by clicking on the name and pressing enter and you can manually choose the color of each mask by clicking on this little color chip here i'm going to delete the second mask and twirl open the remaining one so we can look at some of the other properties inside here first is the path itself which i'll talk more about in a minute next we have mask feather which adjusts how hard or soft the mask edges are this is measured in pixels and is centered on the path so if i set this to 100 it's feathering 50 pixels inside the mask and 50 pixels outside if you need to get really specific here there's a special mask feathering tool that allows you to finesse this as much as you like mask opacity adjusts how opaque or transparent this individual mask is mask expansion lets you either shrink or grow a mask this is also measured in pixels without actually having to change the path itself animating this property can be a very easy way to create an iris reveal for example [Music] one very important thing about masks is that they always move and transform with the layer they're on if you want to move the layer around on screen but keep the mask in the same position relative to the rest of the composition you can actually use the pan behind tool up here to do that pretty cool right in this case though i want to keep the layer itself in the same place but move the mask around to move the entire mask at once you can click on either the mask's name or the mask path property here in the timeline notice how the points change from round when they're unselected to little squares when they're selected we'll just move this around a little bit and then to free transform the entire mask you can double click directly on the path here oops i missed the path and that actually opened this up in the layer viewer which can be useful sometimes but right now that's not what i want let's go back to our composition viewer and being very careful here i'll double click right on the path itself now you'll be able to move it around as well as scale and rotate it to close that out double-click again either directly on the path or anywhere outside of it often you'll want individual control over one or more of these points which after effects calls vertexes if i single click anywhere just to deselect these notice that they've gone back to round dots now i can individually select and manipulate a single point to select multiple points at once you can either hold shift and click more you can grab any straight path segment to move both of those points at once or you can actually drag a box around all the points you'd like to control and move them all at once since after effects is an animation program we can of course be making our mask change over time which i can do by activating the stopwatch here on the mask path property to start creating keyframes so maybe i'll start with this shape here go forward a little bit and then change a few points i know maybe that's not the most exciting thing ever yet but it's the basis of all the other masking work you'll do in the future so it's good to get a handle on how all of this works [Music] before we wrap up let's take a look at a few quick examples of using masks in your everyday work a vignette is a nice use case for a mask they're a nice finishing step for many compositions and can help you direct the viewer's eye to a specific part of the frame let's go up to layer new solid or you could press ctrl or command y i'm going to name this vignette and let's choose a color from our image maybe like this very dark purple here as you can see it's not quite black now we have a solid covering the whole frame which is obviously not what we want but if we come up here to our shape tools choose our ellipse and double click on it it will actually create an elliptical mask exactly the size of our layer this still isn't quite what we're going for so let's come down here and we can either set this to subtract or there's also this little invert button that will quickly invert your mask let's twirl this open crank this feather up to about 350 or so that looks nice and maybe turn up the expansion just to nudge this out a little bit that looks pretty good i might open up the layers opacity and turn this down just to maybe 80 or so i could probably stop there but sometimes it's nice to make your vignettes look a little bit more organic so you can tweak these points a little bit play with these tangent handles just kind of fiddle with this until you're happy there i think that looks lovely another easy way to put masks to work for us is creating a quick little revealer with our image let's start off by just drawing a rectangle i'm going to go ahead and zoom out a little bit so i can see more and i'm just going to draw this one right here on the left half and then this one over here on the right i didn't get them perfect yet but i will in just a second let's zoom back in and i'll hit the quote key to bring up my safe zone display which also has this handy little crosshair right at the center of the composition i'll just grab these edges and move them into place doesn't have to be perfect just make sure that you can't see any seams let's zoom back out and come down here and let's name these appropriately so we have left and we have right great let's maybe go to frame 10 open both of these up keyframe the mask paths move forward a bit and you could either move the entire mask or you could just grab one piece and slide it off to the edge there we go again you don't have to be super precise with this let's highlight our keyframes press f9 to easy ease and just take a look there we go we have a nice quick little revealer it is important to remember that these masks will move with the layer so you wouldn't want to do this until your layer is definitely set in place but this is a nice quick and easy way to wipe off the layer like this just by drawing your masks differently you could make this angled make it a little more complex whatever works for your project so that's the basics of masks in after effects understanding how they work is an essential skill for any after effects artist and this is really just the beginning they can actually do so much more than we have time for today if the possibilities of compositing using these kinds of tools has really piqued your interest you should take a look at vfx for motion taught by industry legend mark christensen if you still need to master more of the fundamental after effects skills like what we covered today you should check out after effects kickstart where noel honig gives you the ultimate intro to after effects don't forget to hit subscribe to get more tips like what we covered today and make sure to check the description if you'd like to download the project files from this video thanks for watching and happy masking [Music] you

Channel: School of Motion

Views: 320,737

Rating: 4.9285488 out of 5

Keywords: Motion Design, Motion Graphics, After Effects, Tutorial, Tips, Tricks, Technique, Learn, Basics, Design, MoGraph

Id: E0ruESAnQ7s

Length: 12min 9sec (729 seconds)

Published: Wed Jul 22 2020