The roundtable meeting that started it all.

"We want to publish and share the knowledge that we've gathered and will gather in the future to promote best practices and standards, because there is an educational process, not only for the practitioners of previs but also for the industries that associate with previs at large. And to cultivate new talent at schools and among educators and students, people that are interested in previs, people that want to study it. There are very few resources for them right now."

The Previs Committee got started at the American Society of Cinemotographers when Curtis Clark, ASC, asked Morin and Frankel to chair a subcommittee on previsualization. At the same time, I hosted a previs roundtable in December 2007 at the Art Directors Guild, which led to the ADG (and later) the VES joining the subcommittee, which was formed in April 2008, met 12 times and was dissolved at its last meeting on Aug. 13.

According to Morin, the previs subcommittee started with a mandate to educate and share knowledge within the film industry on the benefits of the craft. "But early on it became clear that previsualization meant different things to different people, and that it had grown organically into an umbrella for a variety of similar but not identical processes that varied depending on when they took place in the production workflow," Morin explains. "For that reason, in parallel with the education work, the committee also entered in a process of classifying and defining the broad categories of previsualization: Pitchvis, D-vis, Technical previs, On-set previs and Postvis." They also recommended that "previs" should be spelled with an "s" and not a "z":

Previs: a collaborative process that generates preliminary versions of shots or sequences, predominantly using 3D animation tools and a virtual environment. It enables filmmakers to visually explore creative ideas, plan technical solutions and communicate a shared vision for efficient production.

Pitchvis: illustrates the potential of a project before it has been fully funded or greenlit. As part of development, these sequences are conceptual, to be refined or replaced during pre-production.

Technical Previs: incorporates and generates accurate camera, lighting, design and scene layout information to help define production requirements. This often takes the form of dimensional diagrams that illustrate how particular shots can be accomplished, using real-world terms and measurements.

On-Set Previs: creates realtime (or near realtime) visualizations on location to help the director, visual effects supervisor, cinematographer and crew quickly evaluate captured imagery. This includes the use of techniques that can synchronize and composite live photography with 2D or 3D virtual elements for immediate visual feedback.

Postvis: combines digital elements and production photography to validate footage selection, provide placeholder shots for editorial, and refine effects design. Edits incorporating postvis sequences are often shown to test audiences for feedback, and to producers and visual effects vendors for planning and budgeting.

D-Vis (Design Visualization: utilizes a virtual framework in pre-production that allows for early in-depth design collaboration between the filmmakers. Before shots are developed, d-vis provides a preliminary, accurate virtual design space within which production requirements can be tested, and locations can be scouted. Approved design assets are created and made available to other previs processes.