Post production visualisation or 'postvis' is the creation of imagery which merges live-action elements with temporary visual effects, or the creation of new CG shots to provide placeholders for editorial.
Postvis provides the director and editor more visually developed scenes to guide their work before the VFX process begins, especially for sequences with partial sets and in which visual effects drive the story. It also functions as a visual communication tool for the director to communicate with the VFX team.
Similar to previs, to optimise the value of postvis, shots are produced at high speed and are frequently iterated upon or discarded during the process. Postvis helps to provide a visual blueprint for the VFX teams in a shot or sequence and is also used for early stage audience test screenings.
Postvis represents the final stage of the visualisation process and provides some of the foundational design thinking for VFX temps.