#computer generated imagery

Aladdin (2019, Guy Ritchie)

“I hate CGI!!!” yells the grumpy movie-goer. They may not know the proper terminology, but they are actually pointing towards the poorly “green-screened” person in a particular scene. Unfortunately, following modern and general industry definition, keying out green-screen elements is not CGI. It is a very small thing but knowing the difference between VFX and CGI is a key factor in understanding who actually possesses at least some knowledge when complaining about it, which can make all the difference in conversations.

 I personally find it very tiring to hear people speak on topics they know nothing about, and here is no exception. Nothing is free of critique, including visual effects, but the blatant hatred towards this film department that many movie-goers hold does not help towards larger issues like VFX artist job stability, monetary valuing, and general respect within their own industry. The last thing needed is the combined voices of millions of unknowledgeable people dictating one’s job stability, especially when they call every possible thing that was not immediately filmed “CGI”.

 So what are the definitions? CGI is computer-generated imagery, and generally regards elements that were created and rendered in a 3D engine. Digital 2D animation does also fall under the CGI umbrella, yet our focus for now will stay on the most common definition for films, 3D rendering done within the computer. Visual Effects is the larger umbrella that CGI sits within and encompasses a larger range of techniques, from motion tracking, to rotoscoping, keying, matte painting, and the overall compositing that combines all these elements into one. These techniques can sound confusing when in today’s context they are done in the computer (“If VFX is done digitally then is it not computer-generated?”), but that is an odd argument that can begin to delve into calling everything, even colour grading, CGI. It is important to un-confuse and separate the terms in this way for matter of ease, historical context and them being distinctly different concepts.

CGI can exist without VFX. VFX can exist without CGI. Both intertwine and remain very close but are separate. The difference to note is that VFX greatly predates computers, and that CGI must obviously always take place within a computer. Digital VFX techniques of today are not called CGI because they do not historically need a computer to be done. 1857 brought the world’s first visual effects image with Oscar Rejlander combining different sections of multiple film negatives into a single image. Numerous other “optical” visual effects would continue in the following decades as techniques like matte painting, keying and stitching became known, editing and altering the film itself without the use of computer technology.

 The only CGI shot in the original Star Wars: A New Hope involved the Death Star wireframe animation the rebels watched when discussing their battle plans, created by the University of Illinois as the best showcase of what computers could output at the time. The rest of the VFX in A New Hope involved optically keying those famous ship miniatures, beautiful matte paintings placed in front of the camera (originally painted on large sheets of glass, only viewable from one angle), and creating a completely new motion-control camera system that would need to be built again from the ground up by the time Empire Strikes Back began production, questionably functional only because of how new the technology was.