Rotoscoping - Smoke

One of the assessment requirements is to have at least one background containing moving footage.

I have decided to use the smoke coming out of the factory chimneys as my moving footage.

Due to living in 'leafy' farnham I am unable to easily film smoking stack chimneys myself. Therefore, I resulted in looking up stock videos of chimney smoke.
I found a great little video on YouTube of a smoking chimney. The quality wasn't bad either.

After successfully downloading the video I set out to use the rotoscoping tool on After Effects!

The idea was to cut the smoke away from the rest of the footage. This way I could then overlay the moving smoke onto my desired composition. 

 I have imported the footage straight onto After Effects, as I scrub the play head the footage plays. Time to do some rotoscoping.

I've clicked on the 'Rotobrush' tool, this enables me to draw a green line across the area I want to rotoscope. 

The green line does not have to outline the smoke, instead, it just has to act as a basic guide for the rotoscoping reference. 

Once the green line has been drawn a pink outline has been automatically placed around the smoke. The computer has cleverly worked out, with the help of my green outline, that the contrasting smoke wants to be rotoscoped and separated from the sky behind!

As the playhead is scrubbed, the pink outline follows the smoke footage and sure enough it appears to have worked! After a bit of tweaking using the the 'rotobrush' tool a smooth reference is achieved. Now the moving smoke has been isolated from the rest of the footage.

 The checkerboard display shows the transparency behind the smoke. After a bit of tweaking, feathering and motion blur, the smoke moves seamlessly upon its own layer.  

This can now be placed onto a separate composition. Using layers I can now compose this upon my Croydon street scenes. 

I placed the moving smoke onto a new composition and quickly cut out some steam towers

 Here is the final test footage:

This took under 2 hours and I am really pleased with the outcome, this is definitely going to be used in my final film. The smoke could still do with a bit of tweaking though.

Many thanks to Alex for helping me out with this, a good After Effects session this afternoon! 

Time to make a film..!!!