Join Mark Christiansen for an in-depth discussion in this video Quickly create points and Bezier curves, part of After Effects Compositing 05: Rotoscoping & Edges.
- We've had an overview of the pen tool and it's various modes, ways that I like to draw a mask, and how to adjust masks in the timeline. Now let's deal with this tricky section with the orange shirt guy and look further at our options to do that. So my initial thought, and in fact my initial approach, was to remove these trousers basically, the whole lower half of his body and apply motion blur to the key framed masks.
Well that's really cool, but there's a much simpler way, which I'm going to be able to mostly do just in this one lesson. And that's starts with just masking out the guy I want to remove. So reveal just those masks and I'm going to add a third one right here. I draw two corners and then I'm going to add a Bezier over the top. So I can accomplish the entire thing with three points.
Now notice, go back, that I like to to pull out the Beziers as I work. Some other people would draw in the three points and hold down the option key and draw the Bezier later. If you pull it the wrong way, whichever way you draw it, it's going to kink. There's a fix for this in After Effects and that is RotoBezier mode. So, there are two ways to make a mask a RotoBezier.
One is to check RotoBezier and then as you draw a mask, it draws as a RotoBezier. Now notice what happened there, let me do that again. As soon as I draw that third point, the shape of the entire mask changed. And this is the reason that artists don't like RotoBezier. Sure I can select those two points, hold down option and tighten those back in the corners, but it's disconcerting to draw a mask and have it change shape.
I can also right+click on an existing mask and convert it to RotoBezier. Now that magically solved my kinked mask because RotoBeziers were designed not to kink, that's actually the main thing that they do and in fact, I bet you if I convert it back, it still has that virtue. Nevertheless, I don't use RotoBeziers as much. Let's move forward without them. I'll choose opt+m to create a key frame just for this mask and I'm going to say that this mask is going to be called remove orange guy.
Okay, so moving backward we're good, moving forward, and by the way this should be a Subtract mask, in which case I'm going to work in layer view and turn off Render. I've set my first key frame so now I'm free to make adjustments to this mask, which I'lll just do starting right here. I don't need this to be super precise right now. I'm just trying to eliminate all of Mr. Orange and keep as much of the center of the line as I can.
I'm free to do, actually whatever I want, to make this mask work. And of course I could add more points, I'm just trying not to do that. Now notice this isn't perfect, but that's not what people are going to really notice. They're going to notice if that leg gets unusually thin or if any orange pops out, so I'll just keep going. Now notice I don't care about the bottom or left edges, but on the right side I'm being very careful to just split that line between the blurry trousers and the orange shirt, same on the left here.
So you can see I'm using the versatility of Bezier masks to just apply the one mask and adjust the one set of Bezier handles. You may find, when your finished with this roto, if you're playing along, that the main thing you notice is the orange shirt popping, so when in doubt I'm going to eliminate more trousers. This last one is a bit of a puzzle. I'm going to do the same as I did before and rely on paint layer in the process to bring back the detail that I'm now going to knock out.
But I just want to make sure he is really gone. You could probably get away with letting some of his face come through, but I'm just not going to do it. And we're actually clear, given that the red mask has already passed us. So as you've seen, my strong preference is to pull out Bezier handles as I draw, work with as few points as possible, avoid unnecessary work such as articulated roto, and for the most part avoid working with RotoBezier masks.
I just noticed one extra little problem that I really should correct here.... Now let's take a look at animated masks and motion blur.
- Selecting a target
- Applying a mask
- Starting a mask with a shape
- Breaking down shots of clean plates
- Creating points and Bézier curves quickly
- Building articulated rotos with in-between frames
- Adding soft edges and motion blur
- Working with the clone brush
- Getting the most from the Roto Brush