Compositing

As I mentioned below, my interests are in compositing and match moving, I wanted to repeat some of my personal research here to explain these processes.

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Compositing in the modern digital age has two main areas of use; one is removing selected parts of an image to be replaced by another.  Modern digital software can select a colour range on the image to be replaced or removed with ease, this is commonly referred to as blue screening – the pure blue being selected purposely to be removed  (such colours do not generally appear in nature making the software’s job easier and more precise).   This has many practical uses in television and film, a very common application would be a news weather report.  The weather reporter stands in front of a blue screen and the weather map is composited on. 

The second areas of compositing effects are adding an element, for example a cgi character, to an image so it appears seamlessly integrated.  This requires more complex lighting and colour matching, as well as a believably created CGI scene/character.  A good motion picture example would be ‘Terminator 2’ the T-1000 character can turn to liquid metal.  Such a character which reflects the scene on all sides requires a long process of correct colour, lighting matching – but the results speak for themselves.

Today modern digital compositors are a vital part of the film making process; however like many key cogs in a machine, they usually go unseen.  Many recent Hollywood blockbusters rely on heavy CGI use, this is great news for all compositors, as their skills are in demand, with many to choose from my tutor suggested I look at the Transformers series.

In these films giant robots battle each other, fight humans and interact with the environment all seamlessly, this is a perfect example of the importance and quality of modern digital compositing.   

Match Moving (sometimes called Motion Tracking) is an effects technique that is required in order to match CGI elements to live-action footage.  Aspects of the live shot which must be matched are; position, scale, motion relative to live-action objects etc.  and most importantly camera movement.  In fact this is match moving primary focus, so the film camera can be reproduced in the 3D computer program, reproduced to the identical detail of the live-action camera.   There are a few match moving software packages that will track a shot using algorithms.  These programs can track motion very effectively, however match makers are still required ‘on set’ to place markers.  The reason for this, is before the computer software can calculate a 3d camera, x,y,z axis must be specified, with correct markers on the film set the software can pick these up then the compositor can manually select them as axis representations.

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