3 Replies Latest reply on Jan 16, 2017 3:38 AM by Iggorr25

    Clean Plate, removing Actor from video


      Hi Ok so I have this video that you can see in the link, and I need to remove the actor with the tracking markers on him so that he can be replaced with a 3D model character. And I found a great tutorial on how I can do this but I am running in a problem. In the Tutorial at 6:25 he turns the Photoshoped clean plate in a 3D layer and it stays where it is in the comp, but when I do that my Ps clean plate gets moved away in 3D space son re-positioning it is kind of not very possible.... What is this happening, any tips how can I remove the actor? I am hoping I do not have to go frame by frame..... THX in advance.


      The video: SD Video - YouTube


      The tutorial: Quick CleanUp in After Effects CS6 - YouTube

        • 1. Re: Clean Plate, removing Actor from video
          Mylenium Most Valuable Participant

          Well, there's no real 3D camera in the tutorial involved, is there not? Other than that I don't even see why using a 3D layer should be necessary. This is strictly a 2D process.



          • 2. Re: Clean Plate, removing Actor from video
            Rick Gerard Adobe Community Professional & MVP

            You have several problems with your shot. The first is that the sample shot is cropped. You need all the data you can get for camera tracking so do your camera tracking with the original footage.


            Second problem is that there is some lens distortion. AE's camera has no distortion so you'll need to remove the lens distortion to get the best track possible. If you have access to the camera you can do some tests to determine the settings you need by photographing a grid. You also have a bunch of foreground info that can foul up the camera track. This is not a shot for the faint of heart.


            It's going to take some work to cleanup the Camera track so you get a good solid attachment to the background. The other problem you have is that there's perspective in the path the actors move over so you are dealing with more than one plane. A perfect camera track a positioned solid on the background is also going to require that you position a solid on the pathway the actors follow. You will also need another solid for reference to use for the background.

            Screen Shot 2017-01-15 at 11.49.40 PM.png

            Then you can't just replace the path with the Photoshop plate, you'll have to project the Clean Plate on a properly positioned solid so the geometry matches. You'll need two clean plates generated in Photoshop. This is going to be a lot of work.


            This is why you need a visual effects supervisor on the set. When you are dealing with perspective changes and a hand held camera you really needed to shoot a clean plate on set with the camera doing the same moves that it did with the actors. You can then stabilize both shots and line them up using time remapping to generate your clean plate. Without the clean plate from the set on this kind of a shot you are in for a lot of work to recreate the geometry and make the shot work using camera tracking.


            An easier solution would be Mocha Pro's remove module. If you don't have Mocha Pro, then another solution would be to try the Corner Pin / Stabilized technique I demonstrate here: I don't have time to give it a try, but It may be an option for creating your clean plate. You may be able to utilize time remapping and even AE's clone tool to generate the clean plate.

            The next problem that you are going to have is that AE does not have a 3D motion tracker so attaching a model to the actor with the tracking marks is going to be a bit of a trick to do in AE. You would be better off using a 3D app, even Blender, a free open source and very capable but a little difficult to use 3D app with a decent 3D tracker (http://blender.org) to track your actor.


            I hope this helps a bit. If this is a paid gig on a budget you could probably almost pay for Mocha Pro and use the remove module with the time it would save to build your clean plate inside AE.


            Here's Mocha Pro's Remove Module: Basics of the Remove Module with mocha Pro. This is part 3 but it kind of directly to solving your problem.


            BTW, that tutorial you referenced did not give very good professional advice, it was more of a hey I managed to solve a problem on this particular shot by using something I saw someone else do tutorial. IMHO, most of the tutorials you find on YouTube don't point you to the best solutions for problems or teach you how to analyze a problem and come up with a solution. Make sure your vet your trainers.

            • 3. Re: Clean Plate, removing Actor from video
              Iggorr25 Level 1

              Wow! Now this is a bad *** answer THX a lot I am sure I will be able to work out something.
              The original video is a lot bigger and is not cropped, I just exported a small version so I would not have to wait a long time for it to upload to YT.
              The 3D character will be added in inside of Cinema 4D. This is not my project I am just trying to help out someone from a C4D forum.