There are two primary categories of visual effects processes: 2D (two-dimensional) and 3D (three-dimensional). 2D involves work done on images that have only horizontal and vertical dimensions. This includes things like video, photos, graphics, and so on. 3D work involves anything that requires an asset to be built in a simulated 3D space. Let’s do a deep dive into each of these.
The heart of 2D VFX is compositing. Compositing is the art of taking various source materials and combining them into a single final product. Sources might include filmed footage, rendered CG elements, or sourced or created art. The work is done by an artist called a compositor. Every VFX shot, whether it involves simply altering a single frame, combining various pieces of footage, or adding elements such as 3D animation, matte paintings, or graphics, ends its VFX journey in the compositing department. A compositor blends all the elements together and polishes the shot to ensure that all the work integrates seamlessly.
The work the compositor produces is called a composite, but is most often referred to, by industry insiders, by the shortened name comp. Likewise, the compositing process and even the compositing department itself, is often simply referred to as comp. You might hear a phrase like, “These files are ready to send to comp.”
This section aims to familiarize you with basic terminology and concepts used in compositing. We will get into many of these in greater detail later, as we move through the pre-production, production, and post production sections of the book.
In the old days, compositing was done in a variety of ways using in-camera tricks. While on-set a common method involved masking areas of the frame to record only part of the image, then rewinding the film to record on the other side of the frame with the masked area flipped. Similar techniques were used with specialized cameras recording projected images, again to isolate parts of an image to composite with one or more other images. Today, compositing is done almost exclusively on computers using digital files. However, the concept is exactly the same. The goal is to combine images together, to remove parts of one image, and to replace them with other images.
A compositor usually starts by loading the primary VFX plate into a compositing application and then merges additional plates into the shot. A plate refers to a piece of original photography that is intended to be used as an element in a composite. A foreground plate (FG) is usually the primary element positioned closer to the camera which will be placed over the background. A composite often has several foreground elements. The bottom element, or furthest from the camera, over which all others are added is the background plate (BG). The plate the compositor starts with is usually the one that contains the main action of the shot to which all other plates will be matched to.
Visual Effects for Indie Filmmakers: A Guide to Integration and Artist Collaboration is set to publish November 23, 2023. tinyurl.com/VFXIndie