4 Replies Latest reply on May 25, 2012 11:10 PM by Jeff S GP2

    Pixel motion detection?

    Jeff S GP2 Level 1

      Is it possible to have a layer effected by another layers' pixel motion?

       

      Another words, when working with video/image footage....

       

      If there is any change in pixel of layer A  - this turns on the opacity of  layer B.

      If there is no change in pixel of layer A,  the opacity of Layer B is off.

       

       

      Is something like this possible?

       

      Thanks for any insight..

       

      Jeff

        • 1. Re: Pixel motion detection?
          Mylenium Most Valuable Participant

          You simply need a plug-in that extracts the vectors and then you can mangle the channels. The vectors plug-in that comes with Revision FX' Twixtor Pro is pretty much the only option then and it costs money. Though you may also be able to use effects like Time Difference or Time Displacment to mudulate stuff based on temporal differences. It will just be accumulated pixel differences, not genuine vectors...

           

          Mylenium

          • 2. Re: Pixel motion detection?
            Jeff S GP2 Level 1

            Thanks, Mylenium

             

             

            And thanks for the plugin suggestions..

             

            I'll definetely look into those.

             

             

            Cheers!

             

            Jeff

            • 3. Re: Pixel motion detection?
              bogiesan Level 4

              > Is it possible to have a layer effected by another layers' pixel motion?

              Another words, when working with video/image footage....

              If there is any change in pixel of layer A  - this turns on the opacity of  layer B.

              If there is no change in pixel of layer A,  the opacity of Layer B is off.<

               

               

               

              Difference Key compares changes in two versions of the smae shot and the output can be accessed many different ways.

               

              Conventional displacement or compound effects can be driven by comparator operations.

               

              But your description doesn't do me any good. A "change in a pixel" must be defined precisely. I'm not sure vectors of movement are required. One only needs to look at the previous frame. If a pixel has moved, how would you know? If the pixels are binary, black or white, that's easy. If they're full-rez 4:4:4 chroma sampling, that's a bit more difficult.

               

              How about you tell us what you're tyring to accomplish? There's going to be better ways to perform the task, probably.

              • 4. Re: Pixel motion detection?
                Jeff S GP2 Level 1

                My intention is to create an FX overlay triggered by area of moment within footage.

                 

                As an example.  Lets say I have video of a black background with a white square in the middle. When the square is motionless, nothing happens.. When the white square begins to change in position  or size,  This triggers a distortion layer,  thus causing the square to be distorted as it moves..  when the square is motionless, the distortion fx is off.

                 

                 

                  The principal may be similar to that of a motion blur effect, but instead of motion blur, I would like to add my own distortion FX layer.

                 

                Thanks for any ideas..

                 

                Jeff