ARwall green screen technology is looking to disrupt the video post production process. Using Augmented Reality the award winning technology and team has created a way to generate real time backgrounds that the cast and director can see while they shoot.
This product reminds me of the James Cameron system created for Avatar where the director can see the shot in real time. the difference here is the actors can also see and act based on the background projection. It will be interesting to see how it would work with CG characters.
From looking at the videos it looks like unrela engine is what is powering the realtime CG engine like a lot of other AR apps.