7 Replies Latest reply on Dec 28, 2010 12:02 PM by bogiesan-gyyClL

    How do you extend a Greenscreen (virtual set)

    Quay Lewd

      Greetings,

       

      What I have is footage from a video shoot that involved a Greenscreen and have added the SFX in and now need to do Keying. But, the Greenscreen doesn't extend the full length that is needed in order to completely fill up the screen. If I zoom in then I lose a lot of action as it just shows the torso's. So, my question is how do I or can I extend the length of the Greenscreen. (The red arrows indicate where we'd like to extend the Greenscreen) Is there a way to paint in the Greenscreen in the areas that are showing? As you can see from the captured image, the Lightsaber extends out past the Greenscreen so it gets cut off when you key it out. Hindsight is always 20/20 and it would cost us to reshoot the whole thing over. Perhaps there's a way with a Matte or some other method in AE that will allow us to make the Greenscreen longer so that it covers up the background and they I can overlay the background.


      Just a bit of backstory, the Jedi is Miss California 2007 Melissa Chaty http://en.wikipedia.org/wiki/Melissa_Chaty

      The Sith Lord is yours truly. I'm working on a commercial for my production company and this is a great scene that we had hoped would make it in. Any help or advice would be HUGE.

       

      Best Regards,


      Matt Morgan, Director

      Casualty Films

      matt@casualyfilms.com

      www.casualtyfilms.com

      Lightsaber Duel.jpg

        • 1. Re: How do you extend a Greenscreen (virtual set)
          bogiesan-gyyClL Level 3

          Simple application of hand rotoscoping individual masks or using the rotobrush with lots of manual tweaking.

          Unfortunately, depending on your shutter speed, the individual frames will be smeared with motion blur and that makes the drawing of your mask difficult, maybe even impossible on many frames.

          The cost of reshooting is usually less than what you will pay yourself to sit and hand draw each frame.

           

          Suggest your rethink the style or the content of the scene. Can you not place an object in the foreground that obscures the missing screen?

           

          bogiesan

          1 person found this helpful
          • 2. Re: How do you extend a Greenscreen (virtual set)
            Andrew Yoole MVP & Adobe Community Professional

            The purpose of a greenscreen, of course, is to help you cut objects out of an environment without the tedious need to cut out every frame of footage by hand.

             

            The elements of your subjects that fall outside the green screen no longer have that advantage.  They have to be cut out tediously, frame by frame.

             

            Start by using masks to roughly remove the background areas you need to extract (called a Garbage Matte).  You can experiment with the Auto Trace feature, or begin manually rotoscoping the subjects with masks.

            • 3. Re: How do you extend a Greenscreen (virtual set)
              Quay Lewd Level 1

              Bogesian and Andrew,

               

              Thanks for the quick replies. Actually the whole scene is only a couple of seconds long and after rotoscoped the Lightsabers by hand, this is something I'm willing to do. The idea of placing some objects in the foreground, are you referring to placing them in Post, correct? Like a couple of Pillars on either side of the two actors?

               

              Doing a reshoot of the scene (which would be pretty hard to do being that Miss California is in New York right now) would be time consuming and require a lot of work. I don't mind doing the grunt work in AE, it's been a great learning experience. Any feedback on the Lightsabers that I rotoscoped?

               

              Cheers!


              Matt

              • 4. Re: How do you extend a Greenscreen (virtual set)
                Szalam Adobe Community Professional & MVP

                Brave to attempt to shoot an action scene on such a small chroma screen. Unfortunately, I don't think it paid off for you. As others have mentioned, it's tedious hand masking that will be your solution. This technique is called rotoscoping. Here are some great resources on rotoscoping that may help things go faster for you: [link] Lots of useful tips and good tutorials on that page.

                 

                For future reference, when you're shooting an action scene on a chroma screen, it would be a good idea to have a much faster shutter speed on your camera so that you have less motion blur. The more motion blur you have, the worse your key will look and the worse any rotoscoping will look.

                Less motion blur also means tracking the light saber blades would be a lot easier.

                 

                I'm working on a commercial for my production company and this is a great scene that we had hoped would make it in.

                I can understand - being that you're not a post production company - that you would lack understanding of the basics of compositing, but you should really work on making sure you get the production aspect of your shoots done well. Have someone there to watch the monitor and make sure that your talent doesn't go beyond the green screen. (If it's just the light saber blade that goes beyond it, you're golden though and can just put a straight mask there without the tedious rotoscoping.)

                • 5. Re: How do you extend a Greenscreen (virtual set)
                  Szalam Adobe Community Professional & MVP

                  I forgot to address the genius solution suggested. Put some pillars (or something that looks like it would match your background) in front of the problem areas and your whole issue will be solved. Yes, in post. It wouldn't be a bad idea to put some of the same item in the background so it looks natural for them to be there. Ideally your background will be a building with rows of columns...

                  • 6. Re: How do you extend a Greenscreen (virtual set)
                    Quay Lewd Level 1

                    Yes, Szalam, thanks for the input. Again, hindsight is 20/20 and I've learned a lot from the experience. We are a new company and it's these little mistakes that will help us later so I appreciate everyone's advice.

                     

                    Cheers,

                     

                    Matt

                    • 7. Re: How do you extend a Greenscreen (virtual set)
                      bogiesan-gyyClL Level 3

                      gbmatty wrote:

                       

                      Bogesian

                      The idea of placing some objects in the foreground, are you referring to placing them in Post, correct? Like a couple of Pillars on either side of the two actors?

                      Matt

                       

                      Rethinking concepts to fit what one has in hand is a fun exercise. Many effects sequence disasters have been saved by simply stepping away from the original plan and re-imagining a new  plan based on what is available. If you dropped your rotoscoped movie into a 3D scene that included your back plat and a camera that is moving, you could easily place some types of objects into the foreground. Adding a bit of movement to the camera helps sell the scene and makes the whole thing deliberately arty.

                       

                      bogiesan