Join Chris Meyer for an in-depth discussion in this video The basics of variable-mask feathering, part of After Effects Apprentice: 05 Creating Transparency.
In the next few movies, I'd like to demonstrate Variable Mask Feathering, a new feature that was added as of After Effects CS6. In this movie, I am going to show you the basics of using the Mask Feather tool, and while I'm at it, I'm going to show some other ways of the Pen tool changed as of After Effects CS6. Then in the next movie, we'll get into some of Mask Feather tools options. In the third movie, I'll work through a second example; it is more of visual effects bend compared to this graphical example. I've already closed all of our previous comps and if you have access to the CS6 version of the project files, open up VMF_1-Soft Composite*Starter.
You can also use any piece of footage of your own. In this case, I have a graphical clock that I have shown to the client and they say, they like the clock but they wish that the city behind it was a real city, rather than a graphical city. Therefore I need to create a composite where I cut out this clock face and put it over a piece of footage of a real city. Now inside this project file I have such a shot. I'll go down to the Sources folder and look at the Cityscape.mov file. It's a time lapse footage of an actual cityscape. That's what I'll put behind our synthetic clock in this composite.
I'll drag it below, Clock+Skyline inside my comp, so I have got the clock on top of the cityscape. Now if I do not have After Effects CS6, the way that I would normally tackle this, is I would choose the Pen tool, cut out the clock, then use Mask Feather to create a soft edged composite with the footage underneath. Let's walk through that briefly. You can use the RotoBezier option if you would like. I am going to go ahead and use the normal Bezier Pen tool. I'll start by making a point anywhere along the clock.
I like to try to get by with just as few points as possible. I am clicking and dragging because I know I'll want to create a curved Bezier line, so I'll need some tension to my points here. Here is another point, I'll drag it out. If you're careful, you can go back and modify your Bezier handles and even position of some points while you're working. By the way, this is one of the ways in which the Pen tool changed as of After Effects CS6. Normally if you have the Pen tool selected and you hovered over an existing vertex or mask point you would get the Delete Vertex tool.
This resulted in many people accidentally deleting points, when all we want to do is click and move them, that behavior is changed as of CS6, so now you get this Selection tool when you hover the Pen tool over an existing point. If you do indeed want to delete this point, put the cursor over the point, then hold down Command on Mac or Ctrl on Windows and you'll get the Delete Vertex tool. Whenever you've edited a previous point along a mask, make sure you select the last point you've created, that way After Effects knows you want to continue working on that mask shape rather than create a new one.
I'll drag that in position, change my tension little bit here. That point is selected, that's good, and lets come up and close our mask path. I can drag it out a little bit to see what I am doing. I can also double-click this footage to open it up in the Layer panel and the Render check box turned off, so I can see the footage behind without the mask cutting it off, and a little bit of bending of these points. I have got a mask that reasonably cuts out this clock face. And since I'm going to be feathering it I don't need to be precise.
So I'll go back to my Comp panel. I already have Mask 1 revealed. That happens automatically when you create a mask. I type M to close the mask, then type MM, two M's in quick succession to reveal all of the Mask Parameters. To soften this edge I need to use two parameters, the Mask Feather, which softens it both inside and outside the mask path, then Mask Expansion, which pushes the mask outside or inside the mask path. And I'll balance these two values off against each other, until I get it the way that I like it.
Well, maybe so the way I like it, but the client doesn't like this. They say, you know, the way that this clock is oriented in this frame, they really wish they had a narrow feather here and a much broader feather up here. Well before CS6 you couldn't really do that, unless you created multiple masks and mix them together and it got a bit messy. As of CS6 we can use the Mask Feather tool. So I'm going to zero out Mask Feather and Mask Expansion. Go up to my Pen tool, click and hold, and I get the entire list of tool options.
These first four tools existed in earlier versions of After Effects, new in CS6 is the Mask Feather tool. You might notice now that the shortcut key G only appears next to the Pen tool and the Mask Feather tool. By default, G will toggle between those two tools. In earlier versions, it went through all of the tools inside this menu. If you want that old behavior where G went through the entire menu, you can change your preferences underneath General, and Disable Pen tool Shortcut Toggles Between Pen and Mask Feather tools. That will get you back to Pre CS6 behavior.
Frankly, I have gotten used to this and I like it. So I'll back up here, select my Mask Feather tool and let's start feathering this mask. Once you move your cursor over the Comp panel you'll see changes to a stylized feather. You can click anywhere along the mask path. It does not need to be on the mask vertex. It could be somewhere in between, like say here, and drag either upward or inward to decide what direction you want to feather. And note, it's not centered around the masked path, when you create your first feather point, it start the mask path and goes from there.
So it's one way that it behaves different than normal feathering. Let's say I want to go outward, I'll drag it, a nice broad feather up to here. Okay, I've my wide feather here, but I want a narrow feather here. So I'll just add another point either here along the mask path or here on my feather path, then drag inward to create my thinner feather through here. I can drag these points around the masked path and After Effects will automatically interpolate in between those points.
As I demonstrated, you can feather outward and inward. I can just click along the mask path, After Effects will temporarily think that I want a very narrow feather here. But if I drag inward, it says oh, you are trying to feather from an inner boundary to an outer boundary as opposed to from the mask path to your feather boundary. So you have some flexibility there. I'll undo, because I wanted the clock face to be opaque and the feather out from there. I can add as many feather points as I want to go ahead and soften this up.
For example, if I want to be a little bit tighter down here, but wanted to soften it a little wider out here, I just create another feather point. Now if you have just the layer selected, you're going to see just the mask path. You need to have a mask name selected to see the mask path and the feather path. So that's Mask Feathering at its most basic. However, there are a few nice additional options available to the Mask Feather tool as well, and that's what I'll show in the next movie.
The After Effects Apprentice series was created by Trish and Chris Meyer. The tutorials are designed to be used independently and as a companion to their book After Effects Apprentice.
- Creating masks using parametric shapes or freeform with the Pen tool
- Editing and animating masks
- Combining multiple masks
- Using one layer to define the transparency of others
- Explaining the interaction between effects, masks, and mattes
- Mastering mask animation
Skill Level Beginner
Q: This course was updated on 11/15/2012. What changed?
A: We added a movie that shows our premium subscribers how to use the exercise files, We have also added new sets of exercise files designed for After Effects CS5.5 and After Effects CS6.