The Filmmaker’s Toolbox Continues to Expand – On Set Pre-Viz and Compositing

Many of the technologies of today are simply following the same lines of thought that have been extent for years. The computer has made digital all that we used to do optically and with our hands. Over the past week I have spent several hours with the folks at Lightcraft Technology, manufacturers of the Previzion System. The Previzion System is a pre-viz and compositing film-making tool that incorporates green screen photography with backgrounds on-the-fly giving the director a completed composite in real time. The ideas incorporated into the Previzion system have been in place for years but the technology had not risen to the level required to provide such an accurate and reliable system as this.

In the 1980’s Introvision focused on the idea that it would be more efficient to composite in the camera rather than composite all your elements in post on an optical printer. Put your pipeline in front of the camera instead of behind the camera.  The preparation for both the Previzion system and the Introvision system are remarkably similar. With both it is necessary to prepare your backgrounds prior to operating the system on stage but ultimately what you see through the camera is what you get.

The Previzion system is an integration of several sub-systems. Location in space is established by a small, adjustable camera (Intersense IS 1200) that may be oriented up or down depending on whether you wish to place tracking targets on the ceiling or the floor. This camera records the motion of the camera in 3D space. To further increase the accuracy of the system the Airtrack Precision Rotary Tracking Module contains three high-quality electronic gyroscopes that always inform the computer of any motion imparted to the taking camera and smoothes the hand-offs between tracking targets. Of course all this information is stored within the computer for future use.

The Previzion system does not look slick. It has a hodge-podge look that is reminiscent of the early American space program where aerodynamics simply didn’t count in outer space. The aquanaut-aeronautics of the thirties has no application in the vacuum of space.  Boxes and parallel rods protrude haphazardly. What the system looks like doesn’t matter. In the world of entertainment if it doesn’t pass through the lens and get somehow recorded, it never existed. If it isn’t on the film (or equivalent) it didn’t happen.

The common wisdom has been for several years that ultimately the assistant editor on a project will be trained to do a lot of the green screen composites that come up on a show thereby reducing the amount of work done by visual effects houses. The Previzion system begins to sidestep that idea and allows the user to pre-composite on set thereby greatly reducing the labor required for post production compositing. This will prove a great asset to editors as they will have clean, possibly final versions of green screen shots that they can rely upon while cutting the film. I’ve been told that there are situations where final comps have been realized directly from the systems output but I have not personally seen any examples.

Within this system is color correction and contrast adjustment modules that allow adjustments to both the background and the currently being recorded foreground. At this junction the system seems best utilized to acquire elements that will be composited in a composite bay. However the engineers (who incidentally participated in the creation of the Roomba Robot Vacuum of which I have owned four) are continuing to refine the system and should ultimately arrive at their goal of a “pipeline in a box” solution, allowing the creation of final comps on set in real time. Driving sequences for example are excellent candidates for on set compositing. It is not necessary to composite on set however and the motion data along with all the elements can be brought into a composite bay after photography and combined there. All in all it’s a very flexible system. Both Stargate and Zoic have purchased this system in support of their set extension efforts.

The folks at Lightcraft are continuing to upgrade their system and have recently added an animation module into the mix.

If you are interested in seeing a demo I suggest you contact Rick Balabuck at 310.386-7293. There are several examples of the system at work on the net, here are two: http://www.youtube.com/watch?v=ACd8Jn7ZFQ8 [1] and http://www.digitalcinemasociety.com/Popup.php?video=LIGHTCRAFT_NAB09.mov [2].