8 Replies Latest reply on Jul 25, 2014 9:45 AM by Dave LaRonde

    Mask for certain frames?

    pctechtv Level 1

      I would like to have a mask only for a time on my footage. What I mean is.. I have 30 seconds of footage, I want from let say 10 sec  to 15 sec to see only a portion of my footage, the rest of the time I want the unmasked footage. After the play head passes that point I don't want anything masked anymore. The way I managed to achieve it was by double clicking the rectangle tool ( this put mask on whole footage). Then I use hold keyframes to change mask at desired time. Isn't there a way to just tell After Effects to turn off the mask (show footage with no masks) on certain frames. Thanks

        • 1. Re: Mask for certain frames?
          Szalam Adobe Community Professional & MVP

          Your way of doing it works. There isn't a really good way to just "turn off" a mask. You could file a feature request if you would like to see that turn up in future versions: Adobe - Feature Request/Bug Report Form

          • 2. Re: Mask for certain frames?
            Mylenium Most Valuable Participant

            If you know any way to make this more convoluted, then please let us know. Sorry, but you have gaps in your knowledge as big as a truck. A simple layer split or alternatively animating mask opacity would be much more appropriate...

             

            Mylenium

            • 3. Re: Mask for certain frames?
              Szalam Adobe Community Professional & MVP

              Mylenium (as usual) is right, if a bit abrupt. There are other ways to work with masks.

              If there is only one mask on a layer, you might not be able to use mask opacity. And I can imagine not wanting to split a layer if you're still working on stuff with the layer as far as color grading or noise removal. Thus, keyframing the shape of the mask would be a decent solution.

              As I'm sure you're aware, there are a number of ways to do things in AE, so pick whatever works for you.

              • 4. Re: Mask for certain frames?
                pctechtv Level 1

                A simple layer split or alternatively animating mask opacity would be much more appropriate...

                When I turn down mask opacity it make the footage disappear. Yes, there are plenty of gaps in my knowledge that is why I am here. I will concentrate on some formal training to cure my gaps, for now work has to be done, so I will seek the help of this community. Thanks

                • 5. Re: Mask for certain frames?
                  Rick Gerard Adobe Community Professional & MVP

                  There are about a dozen ways that I can think of to achieve your goal.

                  1. Use track matte and simply animate the opacity. You could use a duplicate of your footage with a mask or simply draw a shape layer.
                  2. Put two masks on your footage. The first would be created by selecting the footage layer and double clicking the rectangle tool. The second mask would be drawn to mask out the area you which to hide or show. Then the mask modes would both be set to add and you animate the opacity of the rectangular mask.
                  3. Draw one mask and then animate mask expansion. This would give a nice effect if you also animated mask feather as the mask expanded.
                  4. Use Effects>Channels>Set Channels and animate Set Alpha from Alpha to Full
                  5. Use Effects>Channels>Shift Channels and animate Take Alpha from from Alpha to Full
                  6. If you were using CC 2014 you could use Effect>Channels>Set Channels with alpha set to Off then add a compositing option using the mask and animate opacity

                  Screen Shot 2014-07-25 at 8.27.49 AM.png

                  I could go on and on. If there is any animation required for a mask I almost always use a track matte. I find it much easier to deal with for most projects.

                  • 6. Re: Mask for certain frames?
                    pctechtv Level 1

                    There are about a dozen ways that I can think of to achieve your goal.

                    Thank you so much, that is extremely helpful! Could you also tell this related to it; a lot that I read and even the great members here suggested that I animate Mask Opacity. When I do this it makes the footage disappear not the mask. So is it correct that what happens when you animate a masks opacity you are taking what is "masked" and animating it's opacity, correct? Thanks

                    • 7. Re: Mask for certain frames?
                      Szalam Adobe Community Professional & MVP

                      Add more than one mask to a layer and THEN play with the mask opacity.

                      • 8. Re: Mask for certain frames?
                        Dave LaRonde Level 6

                        ...and another way -- mask the layer, split the layer where you want, and remove the mask from one of the layers.