In its attempt to provide full set of services for its clients, Cinemotion is proud to present its newest addition to its VFX arsenal – the Virtual Studio. Equipped with state of the art Previzion system. This is an evolved way to shoot real actors on a green screen, looking at real time composited backgrounds and even real time CG characters interacting with them. Cinemotion is one of the very few studios in Europe that uses a virtual cinematography system, allowing the filmmakers to work on a green screen stage the same way they used to do it on a practical location. The system combines the live feed from the green screen stage keys the green color and composites a virtual or real life background while maintaining the movement of the camera, the focus shift, the zoom and etc. All this is done and rendered using photo-real rendering techniques with a delay of less than half a second from the live video feed. There are no restrictions for the movements of the camera and it can range from dolly, crane and tripod shots to completely free handheld or steady-cam camera moves.
In order to orient and follow the camera position we use fiducial markers (they are unique circular barcodes) allowing the small optical tracker, placed on the camera to triangulate between the markers and calculate the exact position of the camera in the 3d space of the soundstage.
For acquiring the rotation and the tilt of the camera we use a gyroscopic inertial tracker that gives very precise readings with up to a 1/5th of the degree.
To be able to track fully every move and apply the transforms to the virtual camera, the systems needs to track the lens information and all changes of zoom, focus and aperture. To do this first we characterize each lens in order to get all about its size, distortion, vignette etc. Once that done we have full flexibility to get all changes to the focus, zoom and aperture are send them to the system where they are and applied to the virtual camera settings, resulting in perfect composites with nice depth of field effects applied on the virtual backgrounds shown in real time while shooting.
The system has an interface allowing our fully encoded Technocrane to be used, providing all the tracking information needed, removing the need of using markers or inertial and optical trackers shortening the setup time significantly and making possible to use the system anywhere outside our premises.
The core of the system – the Previzion Software lives in a portable custom build very powerful computer, allowing us to use this mobile system everywhere outside the studio. The software imports, applies materials and renders in real time up to 12 million polygons, plus 8 additional video planes with HD or 4k footage on each. The real time keying process uses production quality chroma keyer, making possible to use the live output of the system as a final result ready to be aired, without any additional post-processing applied. Advanced color corrections are available separately for the foreground and the background. Garbage mattes are available with the option to be connected to any point in 3d space of the stage, providing help with masking any elements in the shot which are not keyed/green screen.
While using the system the director has an access to a custom build IPad application helping him to browse through library of virtual sets, to choose use and experiment with different lenses, positions and camera angles providing real time tracking of the IPad and using it as a virtual camera and a monitor at the same time.
The virtual cinematography system has an interface to our Vicon motion capture installation giving another set of possibilities, by showing full rendered CG representation of the character being motion captured interacting with the live person, both being seen in to the virtual environment.
Cinemotion is building a library of virtual sets, ranging from real famous locations all over the world to some fantastical and impossible to build sets. For more information on those please ask.