2. Tracking

Motion tracking is used in films to allow an effect that wasn't originally in a piece of footage, to follow a subject point through a clip. It is easier to track a point that contrasts well compared to a point next to it, i.e. a black spot on a dalmatian.

For my tracking video, I had an idea of super powers. My first means of doing this involved tracking flames to points on my arm that I would mark with coloured spots. I did film this and edit it using after effects, but I was really unhappy with the results. It was a measly six seconds longs and as you can see, the stock footage I used was very cartoon-like and unrealistic:

After seeing this, I thought I'd try using lightning bolts whilst filming against green screen, using after effects.

I used pieces of coloured tape around both of my middle fingers to track and they worked extremely well against the green background. 

Once I had tracked both points, I parented two null objects to them. To add the electric, I used an effect called "Advanced Lightning" and used the two-way strike. This is where things became difficult.

There are two points in the two way strike: Origin and direction. Normally to make objects move with the now-tracked null objects; I would use the pick whip tool to parent an the object to the null, however, as this is an effect, and not it's own footage; I was unable to do it, so I had to use the expression pick whip to parent each point of the lightning to the POSITION of the null-- not to the null itself. 

Once I had figured this out, it became a lot more straight forward, with only minor tweaks needing to be made to the behaviour of the electricity.

Here is the finished video: 

If I were to film something like this again, I would spend more time on it to rotoscope around my hands, as in this footage, the electricity overlaps onto the back of my hands, making it look less realistic.

(Background for video created by Ben Reeves)