Roto Brush Propagation

Roto Brush Propagation

on Aug 12, 2010 at 7:46:59 pm

Trying to work my way around Roto Brush for the first time, and I'm a little stuck on spans and propagation. If span arrows are going left to right, then I should only be making tweaks by moving forward instead of backward, right?

If so, is there any way to "set" base frames, so if I go through the span and find that only one frame is messed up, I can prevent messing up others by fixing it? Or is there a better way?

Thanks,
Zak

Re: Roto Brush Propagation

by Michael Szalapski

on Aug 12, 2010 at 8:13:35 pm

Did you read all through this and check the linked tutorials? It should answer all of your questions and help you use the tool a lot better. It's got a lot of useful features that aren't intuitive.

- 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.

Re: Roto Brush Propagation

by Michael Szalapski

on Aug 12, 2010 at 8:14:12 pm

Ack! I forgot the link. Here's tons of stuff on Rotobrush

- 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.

Re: Roto Brush Propagation

on Aug 12, 2010 at 9:01:22 pm

Okay, so I can freeze a span, but it doesn't say anything about modifying individual frames. How do I change frames without risking propagation?

Re: Roto Brush Propagation

on Aug 13, 2010 at 4:55:16 am

> If span arrows are going left to right, then I should only be making tweaks by moving forward instead of backward, right?

Correct.

> If so, is there any way to "set" base frames, so if I go through the span and find that only one frame is messed up, I can prevent messing up others by fixing it?

You can extend or shorten a span by dragging its end.

If you draw a stroke with the Roto Brush tool outside of a span, you create a new base frame and a new span surrounding it.

(I'm just repeating what's on the page that Michael pointed to.)

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Re: Roto Brush Propagation

on Aug 13, 2010 at 11:21:51 am

So you're saying to modify just one frame, I have to create a span of one frame?

Re: Roto Brush Propagation

on Aug 13, 2010 at 11:54:18 am

Is there any way to "break" a span into two parts?

Re: Roto Brush Propagation

on Aug 13, 2010 at 3:09:15 pm

> So you're saying to modify just one frame, I have to create a span of one frame?

Yes. But if you're trying to only affect one frame, something odd is going on. Is there a flash of light or other aspect of the image that only appears for one frame? The whole point of Roto Brush is that corrections that you make on one frame are supposed to inform the effect about how to make decisions about the same image regions on the subsequent frames.

> Is there any way to "break" a span into two parts?

No. You'd have to trim a span back and then create a new one outside of it. If you think that being able to split a span would be useful, please file a feature request.

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Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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Re: Roto Brush Propagation

on Aug 13, 2010 at 3:33:58 pm

Well the image I'm working with has a particularly similar foreground and background, so sometimes the propogation process can make things worse as much as it makes other things better. Anywho, thanks for the clarification!

Re: Roto Brush Propagation

on Aug 13, 2010 at 3:41:49 pm

If the foreground and background are extremely similar, it may be time to jump to conventional rotoscoping with masks for that part of the shot.

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Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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Re: rotoscoping

by nitin pannu

on Aug 20, 2010 at 3:50:59 am

pls send mr some more knowledge on rotoscoping.

Re: rotoscoping

on Aug 20, 2010 at 4:16:51 am

> pls send mr some more knowledge on rotoscoping.

Here you go.

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Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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