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Rotoscoping Trouble?

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Low Chuen LeikRotoscoping Trouble?
by on Jul 13, 2011 at 11:50:19 am

Hello all. I'm fairly new to after effects, so pls forgive me if I make myself look like an idiot. I recently found out about Rotoscoping. It has made all my short flicks much easier to make, so thank god for that pice of genius.

But there's a hitch- in fact, TWO hitches. First off, after a few frames, the pink outline seems to reset itself and cover the entire screen. But if I just draw a short green line and proceed, all is well. This makes the entire process tiresome, extending the time to about 1 hour for about a minute. I'm doing this on a solid color screen just to test it out ( i know i can just key it out ). I don't know whether this will prove to be of importance or not, but it always has the frame rate mismatch error. If I set the comp to 59.94 fps like it suggests, the video becomes all shaky.

Secondly, I've seen people transform videos into these animations like hand-drawn lines to form a cartoon of sorts. How do they achieve this? I've watched tutorials on Rotoscoping and have not seen anything mentioning this feature.

Please help me out here, and any answers will be appreciated.

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Michael SzalapskiRe: Rotoscoping Trouble?
by on Jul 13, 2011 at 3:05:30 pm

(This post has lots of links that may - or may not - show up in your email, please read it on the COW.)

There's a lot to rotoscoping besides the Roto Brush (which it sounds like what you're using). Other than using the Roto Brush the fast way to rotoscope is to do so EFFICIENTLY by "keeping your points to the joints."

In-Depth Tips on Rotoscoping from Jeff Kaplan at Point 360 WEST:

Use as _few_ spline curve points as possible to mask the shape -- the less points you have to move, the less time the tedious process will take.

Create as few keyframes as possible to minimize edge jitter and retain fluid motion. If you set keys every frame, it's likely that you'll run in to jittery edges, though sometimes you _have_ to set keys every frame with fast motion. Depending on the source material, you may have a 30 frame clip to roto ... It may be conducive to start with a mask on Frame 0, then one on Frame 30. From that point you could add more keys at Frame 15. Then Frames 7 and 22, etc. (See Point 5 before you do this technique, though.)

Try to keep specific points in your mask corresponding to specific parts of your source material. For example, if you have three points that make up the armpit, elbow, and wrist joint of the edge of someones arm, make sure that you keep the armpit point going to the armpit in each frame. This can be difficult sometimes if there is a lot of movement, but if you don't stick to it, your points will "crawl" around the edges of the object and will cause funky edges and make you have to create more keyframes than is neccesary.

Use multiple masks to generate a matte. There is no reason to try and get the outside edges of a complex shape (such as a person) to fit all in one mask. Make seperate masks for the head, arms, torso, etc. as appropriate and add them together.

Try to pick "natural" keyframe points from the source material and fill add detail as needed. A basic example of this would be if you needed to cut out a person jumping on a trampoline. Obviously, your starting point for keyframes are at the apex and bottom of their jumps. Then you fill in more keyframes in between these points to make the mask more accurate. This is probably a better way to deal with roto than the aforementioned process of just cutting the clip in half over and over (the 0, 30, 15, 7, 22, etc. business) because it pays attention to the natural points of the clip that require keyframes.

Get some good music to listen to. Use the force. Try not to go crazy if you do it all day.

Some more AE specific tips on rotoscoping available here
Such as:
  • Immediately after beginning to draw a mask, press Alt+Shift+M (Windows) or Option+Shift+M (Mac OS) to turn on keyframing for that mask and set a keyframe. This way, you won’t edit a mask frame-by-frame for several minutes (or longer) and then realize that you lost all of your work on previous frames because you forgot to click the stopwatch to make the mask path animated.
  • Draw your masks on a white solid layer with its Video (eyeball) switch off, above the (locked) footage layer. This way, you run no risk of accidentally moving the footage layer when you manipulate the mask, and you can also much more easily apply tracking data to the mask. (You apply the tracking data to the invisible solid layer that holds the mask.) This also means that you don't lose your cached RAM preview frames each time you manipulate the mask. (See Toggle visibility or influence of a layer or property group and Lock or unlock a layer.)
  • Turn on the Preserve Constant Vertex Count preference. (See Designate the first vertex for a Bezier path.)
  • When possible, transform (rotate, scale, move) the whole mask or a subset of the mask vertices instead of moving the vertices individually. This is both for efficiency and to avoid the chatter that comes from inconsistent movement across frames. (See Move vertices in free-transform mode.)
  • Manual motion tracking is less time-consuming than manual rotoscoping. The more effort you spend getting good tracking data for various parts of your scene and object, the less time you'll spend drawing and fine-tuning masks. (See Tracking and stabilizing motion.)

Now, the Roto Brush is not as intuitive as you might think. Read up on it first.

As far as creating cartoon-looking footage goes, there are many ways to do it and many different looks you might be going for. There is a cartoon filter that comes with AE, but it usually looks like crap at the default settings. You'll need to play with it to get it to look good. And, no matter your method, you'll need to shoot your footage with the lighting, set design, etc. prepared to get a good result. For more info do a forum search for Charles Schwab or Waking Life. Waking Life was an entire feature-length film that was footage turned to cartoon and it sparked many discussions on the forums.

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

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Dave LaRondeRe: Rotoscoping Trouble?
by on Jul 13, 2011 at 3:13:34 pm

I'm sorry to have to say this, but if you can't sort out something as elementary as the proper frame rate of your footage, you don't have any business trying to rotoscope.

Since the After Effects user interface can be customized to a certain extent, the terms " the pink outline" and "the green line" are meaningless. Furthermore, you can't draw a single blessed thing in AE, so we have NO clue what you mean when you write "draw a green line".

You're trying to jump into the deep end of the pool, but your profound lack of knowledge of the application means you're wearing lead weights as you dive in.

You need to start with the basics, and in After Effects, there are boatloads of basics. You really do need to learn to walk before you run in AE.

You can learn how to walk here:

And here:

And here:

And Here:

And here:

That's a big list of fine training materials for the AE novice, and I STRONGLY recommend that you check them out.

If you don't, you will become quite familiar with the phrase, "crash and burn".

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA

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Michael TaylorRe: Rotoscoping Trouble?
by on Jul 10, 2012 at 2:35:40 am

I can appreciate you wanting to give advice to someone who definitely needs to start at square one. However your answer seems to lack some sensitivity that I believe is paramount for anyone taking the responsibility to educate. I see this person as an interested individual who wants to accomplish something with a program he purchased.

Your pointing out where he can gain the knowledge necessary to complete his task is commendable, but vainglorious advice can be hurtful, as we are all trying to be artist and we are all at different levels of expertise.

Give, and it will be given to you. For by your standard of measure it will be measured to you in return.

You have supplied Him/Her with a plethora of material to ponder. I would hope with the credentials you signed off with, you haven't lost piety on your way up?

Have a blessed day


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