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N
NAS05
Inspiring
March 7, 2018
Answered

RotoScope and keyframes

  • March 7, 2018
  • 3 replies
  • 3211 views

Hi all,

Im having trouble with using the rotobrush tool. When I set the anchor point and render it through to the end, I go back and fix a few points, It seems to adjust other points and mess up the mask. Is there any way to not make that happen? I've tried the "freeze" button, but then I couldn't make adjustments.

Thanks in advance.

This topic has been closed for replies.
Correct answer Rick Gerard

Rotobrush works only in one direction. You have to watch the progress and pause every time the mask fouls up. The usual practice is to back up a couple of frames using the keyboard shortcuts, make your corrections, and then when you have reached the end of the shot you start over using the refine mask tools. Rotobrush and several other semi-automatic roto tools on the market require this same basic workflow. If you back way up and add a new stroke or subtract something then it will start analyzing the frames all over again.

I strongly recommend that you spend at least an hour going through the rotobrush help files and tutorials that you can find by typing rotobrush in the search help field at the top right corner of AE. It is not an easy or intuitive tool to use. When it works it can be a significant time saver, but the shots it works well on are pretty limited. As you get better at it you'll figure out ways to make it work better for you and you will quickly learn what shots are not going to work at all.

3 replies

Mylenium
Mylenium
Legend
March 7, 2018

When I set the anchor point and render it through to the end, I go back and fix a few points, It seems to adjust other points and mess up the mask. Is there any way to not make that happen?

Well, then likely the Rotobrush tool is not appropriate for the given task. It's really as simple as that. Bad workflow. Use traditional masking, painting and tracking.

Mylenium

N
NAS05Author
Inspiring
March 7, 2018

Well I'm new to this. So i'm not quite sure whats a good work flow over a bad. Like Rick stated-

I strongly recommend that you spend at least an hour going through the rotobrush help files and tutorials that you can find by typing rotobrush in the search help field at the top right corner of AE. It is not an easy or intuitive tool to use. When it works it can be a significant time saver, but the shots it works well on are pretty limited. As you get better at it you'll figure out ways to make it work better for you and you will quickly learn what shots are not going to work at all.

and thats what I've come to figure out. The clip has to many simulator colors for Ae to learn and its getting confused. So I will work on Ricks and Roland's advice moving forward with this and future projects.

Thanks everyone for your help! I appreciate it

Roland Kahlenberg
Roland Kahlenberg
Legend
March 7, 2018

By default, Rotobrush propagates its information forward and backwards, 20 frames each direction This is known at Rotobrushes Span. If you create a new Rotobrush Base Frame and look closely at the Span, you will be able to see two sets of chevrons (arrow heads) on either side of the Base Frame going into opposite directions. To prevent propagation or to lengthen/shorten propagation, you drag the edge of the Span to suit your purpose.

More info here - Roto Brush and Refine Matte in After Effects

Very Advanced After Effects Training | Adaptive & Responsive Toolkits | Intelligent Design Assets (IDAs) | MoGraph Design System DEV
R
Community Expert
Rick GerardCommunity ExpertCorrect answer
Community Expert
March 7, 2018

Rotobrush works only in one direction. You have to watch the progress and pause every time the mask fouls up. The usual practice is to back up a couple of frames using the keyboard shortcuts, make your corrections, and then when you have reached the end of the shot you start over using the refine mask tools. Rotobrush and several other semi-automatic roto tools on the market require this same basic workflow. If you back way up and add a new stroke or subtract something then it will start analyzing the frames all over again.

I strongly recommend that you spend at least an hour going through the rotobrush help files and tutorials that you can find by typing rotobrush in the search help field at the top right corner of AE. It is not an easy or intuitive tool to use. When it works it can be a significant time saver, but the shots it works well on are pretty limited. As you get better at it you'll figure out ways to make it work better for you and you will quickly learn what shots are not going to work at all.

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