2 Replies Latest reply on Mar 29, 2014 2:33 AM by MizamookFilmworks

    Rotobrush changing behavior at frame




      I am having a problem that seems to be unusual in that I cannot seem to find it on any AE rlated forum, or in any tutorial, or any set of instructions.  I've used Rotobrush before, not extensively, but with success after a lot of patience.  I'm not skilled, but learning.   I usually use AE for stabilization, removing bugs from timelapses, and color work.  Very very slow/new with more advanced stuff.  I can animate/mask in Vegas Pro a lot easier than AE, if that is any indication, but I'll get better as I learn.


      In using Rotobrush to clear the area behind a flapping flag, which usually covers the entire frame, but in the instances it does not, I'd like to see the image behind it (another layer)



      In this comp, I've got another layer isolated with Rotobrush and Paint - successfully frozen.  Of course, this layer has Rotoscoping on every frame. 


      In the flag layer, it is my suspicion that I need to go back and let is create contiguous segments even though there are seconds during which I need no Rotoscoping.  However, doing this just adds to the time it takes for me to do anything.  I'd like to work forward, but be able to go back and touch up if necessary.


      Why is it not possible to freeze only selected segments or sections rather than the whole Rotobrush instance?  (that's one question I keep asking as I open/close different comps)  I'm not done with this one, but if I close it so I can work on a different clip, I have to wait a while longer than I have patience for since it does not propagate if I go to some other window/program ...in other words, it hijacks my computer.


      OK< so anyway, here's the issue:  I've got a section of the flag successfully masked with Rotobrush.  Then the flag fills the entire frame again, and a couple seconds later an area of sky appears behind it so I start to roto again.  Immediately it creates a 10 frame forward and 10 frame backward span.  I don't want it to go backward at all, in this instance.  Do I have to count frames? 


      So I deal with that, and am Rotobrushing forward, and I get to frame 11 past where I started, and I recreate a new base frame, and go all the way to the end of where the flag reveals sky, and now is filling the frame again, so I go back and start to Refine Edge.  All is well until I get to the frame just past frame 11, whether I created a new base frame or not, in this area (not always the same - it is not the clip!) suddenly the entire layer preview turns gray, or pink, depending on the mood of AE, or whaever it is that I am doing wrong.  I can't get the pink frame to show up again, but I can undo the refine edge, and now I see the mask in the area (upper corner near the edge of the flag) has a bunch of pink lines in it, like there are multiple rotobrush instances piled up and confusing things.


      So I'd like to not redo this entire section (yet again) after deleting all the spans in the area, especially as patiently doing this multiple times has no good effect.


      What am I doing wrong?  Again, I can find no reference to this anywhere.


      EDIT:  The gray goes away if I delete the Refine Edge after the second base frame.  But it comes right back after I try to get the next two frames worth of refine edge...each frame, regardless of order, causes the gray.  Still haven't seen the whole frame pink again.








      AE CC (current)

      Windows 7 Home

      Sandy Bridge i7-2600

      16GB RAM

      C:\ 160GB SSD

      3 1 TB Caviar Black Media Drives


      Rotobrush Flag bad frame.JPGRotobrush Flag Good frame.JPG

        • 1. Re: Rotobrush changing behavior at frame
          Rick Gerard Adobe Community Professional & MVP

          Your workflow is a little off. Rotobrush should be used on an entire segment of a clip and then frozen and used. If you have multiple sections of a clip that need separate roto work then divide up the work.


          Here's what I would do with your clip.

          1. Split the clip at the start of every section that needs roto. IOW, if your flag is full frame at frame 0 and at frame 100 a corner of the flag reveals the background and continues to show the background until frame 150 then split the clip at frame 100.
          2. Repeat this procedure until you have every section that needs roto work on a separate layer.
          3. Use Rotobrush to roto each separate layer and freeze the layer when you have a complete segment masked to your satisfaction.
          4. Render the entire masked comp to a frame based production codec with a straight alpha channel. I would use either Animation codec QuickTime or Jpeg2000 to create your DI (digital intermiediate).


          You now have a clean single video clip with an alpha channel that you can use to complete your project. In the long run, this will be the fastest and most efficient way to complete your project. In most cases you are better off creating the individual elements of a complex composite and rendering them with transparency (Straight Alpha, never pre-multiplied) than trying to handle a bunch of layers with roto, keying, or other transparency effects applied in a single comp.

          • 2. Re: Rotobrush changing behavior at frame
            MizamookFilmworks Level 1

            Hi Rick,


            Thanks, sounds like what I was starting to suspect.  Indeed, I have use of this roto'd flag after this clip creation, so rendering an Animation with Alpha seems best for the long run.  In fact, I should go an render out my top roto layer too.


            So, to step backward without losing a lot of work - 2 questions:


            1.  Can I split the already roto'd layer sections into individual layers or do I need to bite the bullet and start over with sparated layers?


            2.  Is there a way to mass delete Refine Edge without deleting the span or gong through frame by frame?  The problem does not come into play until I go past the first span with Refine edge (actually the FIRST section is fine, which is what is weird)


            Thanks again!