Watching Water Vapour in The World

Seen as most of my visual effects shots consists of compositing smoke, I have been keeping my eye out for smoke and steam in every day life, eg. clouds, piping hot soup and my weekly shenanigans as an arsonist.

The clouds give you an idea of how light reacts, creating hot spots. The shots so far have no strong light source directly behind it which would give a high level of over exposure, but there are subtle effects needed. At the moment, I am using pre-shot archive footage of smoke, dust and atmospheres. This is pre-lit and therefore in order to give it the effect of being situated in the same environment as the footage, other techniques are required.

It may be obvious to point out, but in order to composite them best there are a few important measures: set the blend mode to 'screen', use a light wrap (generate light wrap only and merge, and premult for the roto to work properly) and colour correct it so it looks part of the scene more but still retains its grey opaque tone.

In order to get a more accurate consistency, along with the above examples, I have used a glow and luminance keyers to pull out values to be brighter. In more obvious areas I have roto'd areas I want to make brighter or darker and applied them on top of the full plane of smoke, adding to them.