2 Replies Latest reply on Apr 10, 2011 12:21 PM by petecrown1

    Roto Brush: Propagate changes to subsequent frames?

    petecrown1

      I'm still fairly new to this so please accept my apologies if I get
      certain things wrong... :-/

      Thanks to Chris Meyer's lynda.com title on New Creative Techniques in
      AE CS5 I discovered the Roto Brush tool.

      I've got this clip of me, in sitting position with some undesirable
      background.  I'd like to get rid of that background using the Roto
      Brush tool.  So with some polishing and tweaking I created the base
      frame in AE.  Then moving forward to the next frame I corrected some
      errors that occurred again.  However, going forward to the next frame
      it seems as though Roto Brush does not propagate the corrections I
      made on the last frame to the frames ahead.  When I jump to subsequent
      frames the same mistakes still occur and I need to correct them again.

      This is pretty tedious considering that I'd like to correct
      approximately 30 seconds of a clip (25fps). That would be 750 frames,
      ouch...

      So obviously I am missing something here. Or is this normal
      considering that I used a Sony HDR-SR5E and not a top notch camera
      with better defined edges?

      Any help is much appreciated.

      Thanks!

        • 1. Re: Roto Brush: Propagate changes to subsequent frames?
          Rick Gerard Adobe Community Professional & MVP

          If you're in the right window (footage not composition) then the Roto Brush should track for several frames. There is an indicator at the bottom of the Footage window. It will show an orange indicator at the starting poing and a green line for tracked frames. You start at the first frame, then let it track on it's own until it starts to drift or you run out of frames. Tracking is done by pressing the space bar. Now you make your adjustments. Roto Brush will now indicate the new frames that Roto Brush will automatically track. Double check the track before you continue and make any necessary adjustments. Once the tracking is complete Freeze and Render your Roto. If you do not freeze the roto at the end and you go back to the second frame to make a small adjustment you'll have to start again because this tool only works in one direction. New adjustments start a new track.

           

          I hope this helps.

          • 2. Re: Roto Brush: Propagate changes to subsequent frames?
            petecrown1 Level 1

            That's a great tip, Rick. Appreciated it!

             

            Just today I did in fact go back to an earlier frame just to find out that I had to adjust subsequent frames all over again... :-/ So freezing will certainly help.

             

            So would you click on the "Freeze" button every 100 or so frames or only when you're completely done with the adjustments and want to move on to the next task of refining the Matte?