5 Replies Latest reply: Jun 1, 2012 5:46 PM by captain_astronaut RSS

    Using Rotobrush with time-lapse sequence

    captain_astronaut

      I shot some timelapse of an artist drawing a model, and I'm trying to remove the background like so.

      Rotoscoping.jpg

      However, every couple of frames I have to fix the lines where I drew and it's getting to where I have to fix nearly every frame. There are a ton of frames, plus two other angles I shot. I only saw some video tutorials on how to use Rotobrush, but there must be something I'm missing, or maybe there's ways to make this work for me better. Please let me know what further info you require (I'm using CS6).

       

      thanks in advance

        • 1. Re: Using Rotobrush with time-lapse sequence
          Andrew Yoole ACP/MVPs

          I don't think you're missing anything.  Rotoscoping is slow, tedious, horrible work.  The footage you're working on has detailed, complex backgrounds and can't be easily separated from the subjects by any software operation.  Perhaps you have the ability to reshoot the footage against a green or blue screen so it can be keyed?

           

          You may find you can work smarter by using individual masks for objects that move, such as legs and arms.  So, you have a fixed mask for the static elements like chairs, then sperate masks for man's foot, man's leg, that sort of thing.

          • 2. Re: Using Rotobrush with time-lapse sequence
            Mylenium MVP

            What Andrew said - roto is tedious, boring, labor intense and expensive, that's why ILM, Digital Domain and others have offshored it to China, India and other places these days. If you can, reshoot it. Otherwise you might help matters along by pre-composing/pre-rendering and cleaning up parts using masks. The chairs and canvas for instance probably do not move that much. And generously remove the excess areas left and right, top and bottom. Once that's out of the way, you can focus on the critical parts, but even here I'd probably use masks for the parts that don't move that much and only do the rest with brushing. And if you haven't noticed already - it helps a lot to have a tablet for these kinds of jobs...

             

            Mylenium

            • 3. Re: Using Rotobrush with time-lapse sequence
              captain_astronaut Community Member

              I'm a TV editor by trade, but wanted to try this out on my own time. I used AE once, 10 years ago and it freaked me out.

               

              When you say "pre-composing/pre-rendering and cleaning up parts using masks." What exactly do you mean. I'm pretty sure you mean masking out the huge areas that I don't need, but what's pre-composing/pre-rendering?

               

              By a tablet do you mean a Cintique or an Intuos? I'd love a Cintique, but those suckers are pricey. I'd also love to have an intern do all my scut work.

              • 4. Re: Using Rotobrush with time-lapse sequence
                Mylenium MVP

                Put your clip in a comp, then use that comp as a layer in your other comp. Mask the footage in the nested comp, add refinements in teh main comp. I recommend you read the online help on nesting/ pre-composing as wel las pre-rendering.

                 

                Mylenium

                • 5. Re: Using Rotobrush with time-lapse sequence
                  captain_astronaut Community Member

                  Thanks guys, I'll have to read up. But I'm glad I wasn't missing something and doing it the hard way. If I had thought of this before shooting I would've done something differently, like get some lights in there to separate them a little more from the the background. As it was, I just had the overhead flourescents.