4 Replies Latest reply on Apr 1, 2012 3:51 PM by JesseHarris

    Case For Rotobrush & Mask Keyframe Question

    JesseHarris Level 1



      Just wanted to make sure the below sample is a case for Rotobrush.  Obviously I've never used it before, however I'd like to maintain the color, (excuse the crappy mask), I've created in the water in the first shot, throughout the sequence of cuts.  When the woman moves across the aquarium, I'll need to rotoscope her correct?  Any tips?  I will however be reading the manual!




      And the mask question - I should know this but for some reason, (in another comp), my mask changed shape over thime.  It was the same tank you see above, but it was a dolly shot and the tank didn't change shape!  You'll laugh but I ended up resetting the mask points in 291 frames, and it still didn't work as the variations in mask shapes created a flicker after applying color correction, levels etc.


      Shouldn't I be able to go to the end of the comp.  Draw the mask shape I want, keyframe Mask Shape; then go to the beginning of the comp - set the position of the mask and keyframe again.  Please tell me where I'm going wrong!


      And; is there a way to keyframe a "transform" of the mask shape during time?  Essentially changing the size and shape of the mask, I was only able to do this frame-by-frame.


      As always, much gratitude for everyone's guidance, patience and knowledge!





        • 1. Re: Case For Rotobrush & Mask Keyframe Question
          Mylenium Most Valuable Participant

          Sounds like you used auto-trace or something on the mask? Or did you add vertices inbetween? Move the layer? I can't quite picture what you actualyl have done, but probably deleting all keyframes and starting over would have been faster and cleaner... As for the otehr matter - yeah, it could be done with Rotobrush, but I would simply draw a mask on a solid, use it as a track matte and pin its position using keyframes or tracking. No need to be afraid of masking. Even when done manually and with AE's awfully slow masking system it is still many times more efficient and faster than trying to fix up a bad Rotobrush or green screen key...



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          • 2. Re: Case For Rotobrush & Mask Keyframe Question
            JesseHarris Level 1

            I actually wasn't using auto-trace, I drew the shapes with bezier points as one would in PS.  Not sure what you mean by vertices?  Didn't move the layer.  My apologies for not painting a better picture.  I'd like to post a screen shot, but don't see the camera icon!  How do I do that, is it possible without the hassle of using flikr or photobucket?


            Ok, not quite sure if you answered my question, (and yeah, my 291 frame marathon freaked me out a little.).  How do I maintain the shape of a mask from beginning to end of a comp?  (there will be variations as it comes into frame etc., I think I can handle that), but why wouldn't the mask hold shape when I keyframed beginning and end?


            Now, with the above referenced Vimeo clip, the shot where the artist crosses the aquarium - won't that require multiple mattes on multiple solids, or layers as there are a bunch of spaces where we see the aquarium?  AE will not allow more than one mask on a layer correct?  Unlike PS!!  Or am I wrong about that?


            Would I be linking the solid with the matte(s) to a null object and then tracking that?


            Many thanks again for your time - I hope my questions aren't too convoluted!



            • 3. Re: Case For Rotobrush & Mask Keyframe Question
              Mylenium Most Valuable Participant

              Vertices is just another word for anchor points/ knots in the path. Not sure I understand the rest of your post this late in the evening. My brain is pretty munched... You can move masks in their entirety by just double-clicking. This will invoke the free transform box. Therefore this would be an easy way to retain the overall proportions. AE can have an infinite number of masks per layer (well 9999 or so at least) and they even have boolean modes for further fancy. This is not different than PS, in fact its even more versatile since you can reorder the masks and change their modes without invoking obscure keyboard shortcuts. I recommend you look that up in the help. When tracking, you would link the solid's position, since mask points in AE themselves are not trackable. Again, look it up in the help or study a good tutorial (like the ones from Mathias Möhl).



              • 4. Re: Case For Rotobrush & Mask Keyframe Question
                JesseHarris Level 1

                Thanks very much Mylenium, thanks for the clarification of vertices - they're what I used!  More layers of the onion to tear off...  Thank you for the glimpse and I will do my homework more thoroughly.  The access to greater minds and experience than mine here is invalueable and I'm much appreciative.


                Rest well then and clear you mind for MONDAY :-)