Join Todd Kopriva for an in-depth discussion in this video Variable-width mask feathering, part of After Effects CS6 New Features Overview.
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In After Effects CS6, masks can have variable variable-width feather. Feather refers to the areas of semi-transparency in a mask. And in After Effects CS5.5 and earlier, a mask could only have one feather value all the way around. Let's see what it means to have variable-width feather and masks and after-effects CS6. First, let's consider a motivating example. In this shot here, we have a moving aircraft that has motion blur. So, in the direction of it's motion, there's blurriness.
But perpendicular to the direction of motion, everything is nice and clear. If we need to draw a mask around this object to separate it from the background, such as in rotoscoping, we need to be able to have a soft, feathered mask around these areas of motion blur, but not have feathering around these areas of crisp, sharp edges. Let's look at a simpler example for illustration purposes. Let's create a new composition. Click OK. Make a new Solid by pressing Ctrl+Y or Cmd+Y on Mac OS. Make it composition size and make it white.
Click OK. And just draw simple electrical mask. Using Ellipse tool, drag in the center of the layer. In previous versions After Effects, you could press F to expose the mask for the property, as you can still do now, and increase feathering for the entire mask. You could unlink here and feather in one direction or the other.
I'll undo that by pressing Ctrl+Z. But now and After Effect CS6, you have much more control over feathering. I'll choose the new Feather tool, which shares a button with the Pen tools. And I'll click on the mask at any point. This dot right here, with the black center, is a new mask feather point. If I drag on that, I get much of the same result that I got in previous versions of After Effects by increasing the Feather Value.
If I drag all the way back to the edge of the layer, there's no feathering at all. I can add another feather point. I'll add one down here. And now, if I pull on this feather point, notice I'm getting different feathering all the way around the mask. And if I go back to my other point, I can pull it around and get various combinations of feathering, as each of the mask feather points is influencing the feathering.
I can drag it around the mask or I can use keyboard shortcuts. If I press the Up Arrow, the selected feather point moves away from the mask. If I press the Down Arrow, it moves back toward the mask. If I press the Left Arrow, it moves counterclockwise. If I press the Right Arrow, it moves clockwise. If I hold the Ctrl key and position the Feather tool over a feather point, it turns into the Feather Delete command. So, if I click, that's gone.
I'll do the same here and remove that one. And I'm back to having no feather points. I'll go ahead and add those two back. One and then the other. And now, on an edge between them, I'll create yet a third and notice when I pull this one out. There's feathering between these two but not around this edge.
I'll Deselect all by pressing Ctrl+Shift+A, and notice the result here. This looks very much like the sort of mask that we need when we're masking Motion Blur, as we have crisp edges here and here, but a nice smooth fall-off here, in the direction of motion. You can also make feathering happen inside the mask when you create a new feather point. Instead of dragging out, simply drag in toward the center. Note that if I have both outer feather points and inner feather points, they interact in some interesting ways.
Once a feather point has been made an inner feather point, you can't drag it across the edge to make it an outer feather point. It simply stops at the mask itself. And same here, I can't make an outer feather point into an inner feather point by dragging it across the mask path. Notice that there's a box next to the Feather tool right now. That means that if I were to drag, I would create a selection box. If I drag at the selection box around multiple points, and they're all selected, then the keyboard shortcuts that I use, such as the Up Arrow key or the Down Arrow key or the Right Arrow key or the Left Arrow key.
I'll apply to all of the selected points. I'll hit Delete. And all of those selected points are removed. Handy short cut is the G key. Note, I have the Feather tool active right now. If I press G, it becomes the Pen tool. If I press G again, it's back to the Feather tool. You can see that keyboard shortcut here, with the G and the G for just the Mask Feather, and Pen tools. But that's not the behavior that existed in previous versions of After Effects, where G could toggle between all the various Pen tools, such as the Add Vertex and Convert Vertex tools.
So, if you want the old behavior back, you can go to Edit > Preferences > General, and deselect Pen tool Shortcut Toggles Between Pen and Mask Feather tools. We'll go ahead and deselect that, click OK. And now, note that G is a shortcut for cycling between all of these tools. So, now if I press G, and again I press G, I press it again, and I press it again. I'm cycling between all of the various Pen tools.
I actually prefer the default behavior. So, I'll go back to Edit > Preferences > General, and check that. Click OK. Note that you can get a lot of information about Mask Feather by paying a lot of attention to the Info panel as you interact with Feather Points. For example, if I create another feather point, if you look in the Info panel, you'll see some information about it, including the fact that it's using the Smooth Fall Off type instead of Linear. And if I Alt+Drag or Option+Drag on Mac OS to change the tension, the Info panel tells me what tension I'm using.
It's easier to see tension when I actually have an non-zero feathering. So, I'll do that again, pressing Alt while I'm dragging back and forth. So, in general, pay attention to the Info panel if you need more information about your feather points. So, you now have much more control over how semitransparent areas around a mask fall off using the variable with the Mask Feather features in After Effects CS6.
- 3D animation
- User interface changes and removed features