4 Replies Latest reply on Aug 14, 2012 7:47 PM by Rick Gerard

    After Effects : Warp Stabiliser issues

    davidtimperley Level 1
      I've been hitting the Warp Stabiliser in After Effects pretty hard and have noticed that it likes to get distracted by moving objects in a scene.

       

      I can't work out what is the triggering factor? It's attention will wonder, even if there is relatively stationary content present in the image.

       

      Here is an example video...

      https://www.youtube.com/watch?v=C_F57iP3tSQ

       

       

      I thought that I could fix some of the issues by dialing 'stablisation' in and out, but there is no way to turn the 'smoothness' up or down.
      Strangely Adobe hasn't included a handy animate stopwatch button on any of the Warp Stab. functions apart for the 'additional scale' option.

       

      It would be nice if we could define an area with the mask tool and have the Warp Stabiliser use the area under the mask as it's reference data.
        • 1. Re: After Effects : Warp Stabiliser issues
          Mylenium Most Valuable Participant

          It works as it should. It's built on motion field synthesis. It's like a pool where you're watching the floor tiles - you are trying to straighten out the floor tiles, but any extreme disturbance in the water surface will prevent that, be it a big stone thrown in or some soft ripples that bounce back and forth. Or in other words: As long as the motion field is relatively stable, the warp analysis will work, but as soon as radical changes occur in short time or noise is preventing determining a "flow", it can't do its magic. Whether or not there will ever be ways to let the analysis ignore parts or pin shapes e.g. using masks as edges, is pure speculation at this point. For now it's up to the user to make educated decisions when to use it and when not. It's noit a universal cure to any shake problem nor was it ever meant to be.

           

          Mylenium

          • 2. Re: After Effects : Warp Stabiliser issues
            Rick Gerard Adobe Community Professional & MVP

            There are some shots that even Bijou won't track and stabilize automatically. There is usually a solution somewhere but some solutions require a lot of hand work.

             

            If you want to isolate an area with a mask then, and this only works in some cases, mask out the problem area inside the pre-comp, then stabilize, then turn off the mask. Animating the smoothness solution isn't an option because of the math used in the calculations. For relatively static hand held shots without a lot of reflections Warp Stabilizer works very well. When you have reflections all over the place from curved surfaces or elements that are moving in the scene that overwhelm the background you start running into problems.

             

            I once had two takes of a shot walking through a lobby, through some doors and then around some tables. One tracked and stabilized quite well with AE's motion tracker. The other didn't work at all. The angles were slightly different and the number of people in the scene changed. The biggest problem was probably a guy that filled about half of the frame for about 60 frames wearing a plaid shirt. There was just too much detail in his shirt and too little detail in the background to get a good track.

             

            You can mask out interfering areas, pre-compose the shot, stabilize, then turn off the mask in the pre-comp. This would work for the car and fix the problem with the first example.

            • 3. Re: After Effects : Warp Stabiliser issues
              davidtimperley Level 1

              Thanks for the comments.

               

               

              What concerns me with using this feature in the future, is the unpredictability of it's 'solves'.

               

               

              Warp Stab works great for most things, including the little girl in the example video, but her arm flying out suddenly ruins the track?!?!

              I had a long section of footage that I wanted to use. The Plug-in didn't flinch at her bouncing about or other limb moments. The reaction to her arm was the only error, and I was compelled to remove Warp Stab from the entire section to maintain continuity (link to final piece https://www.youtube.com/watch?v=P_tEqSgDjLg ).

              Despite the plug-in being extremely speedy, I feel that now I'm going to have waste some time doing a 'test run' to see what unpredictable event will break the effect.

               

               

              I chose all of these examples deliberately to illustrate common video content that we have to deal with. Bread and butter stuff.

              There are no radical camera moves, outlandish colour combinations, or extreme lighting set ups.

              These are the sort of shots that an editor might say 'chuck Warp Stab at it cause there is nothing worth spending a lot of time on in here'.

               

               

              I appreciate the 'ripples in a pond' example, which is why I was disappointed that there is no way to 'dial in/out' or 'dampen' the effect.

               

               

              Isn't Bijou like ten years old? I would have thought that technology would have moved beyond it's capabilities?

               

               

              I feel that this feature should be more accurately titled...

              The 'Smooth out any motion when someone is moving along a liner path' plug-in

              • 4. Re: After Effects : Warp Stabiliser issues
                Rick Gerard Adobe Community Professional & MVP

                Bijou is constantly updated and state of the art. It's very expensive because it does things other trackers are not capable of.

                 

                Sometimes the simplest things can spoil a shot. The little girl shot can be easily fixed by using a mask to hide the spot where the movement throws off the track, pre-composing, stabilizing, then removing the mask. Same thing with the other shots.

                 

                My usual workflow is to try the stabilizer. If it doesn't work, figure out what is throwing off the track. Draw a mask around it, invert the mask, pre-compose moving all, then stabilize the pre-comp and then remove the mask. In most cases this solves a problem shot completely in just a few moments.

                 

                If those solutions don't work I move on to something else. BTW, if I were directing any of the sample shots the camera would have been on some kind of camera support. I didn't see any production reason for shooting hand held. That's not a criticism, just a suggestion for some more thoughtful production planning.