While Previs is a collaborative process that generates preliminary versions of shots or sequences, predominantly using 3D animation tools and a virtual environment. There are several other similar techniques in use today. Using digital tools these are used by various relevant departments of the film production crew.
• 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. (Although pitchvis is not part of the main production process, it allows people like executives and investors to take a first look at the potential result.)
• 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. (In good practice, even preliminary previs is most often based on accurate real-world data, allowing technical data to be
more easily derived.)
• On-set previs creates real-time (or near-real-time) visualizations on location to help the director, VFX Supervisor, 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 designs. 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 preproduction 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 previz processes.
In recent years, digital previs (in virtual 3D space) is playing a more and more dominant role. It offers a path to new forms of filmmaking (see later section on advanced  techniques). But traditional practical previs techniques also continue to provide economical ways to communicate desired action and imagery. Regardless of the technique chosen, the principal goal has always remained the same. By developing and then expressing the intention of a sequence in an accessible visual format, successful previz increases the likelihood that that intention will eventually be realized.