A work in progress. In this technique, we are changing the color of the eyes to achieve a look of paranormal possession. This is done using the tedious technique known as “rotoscoping”.
In this case, there is a small piece of digital film of each frame that is meticulously cut out, or “masked” and animated to remain on point throughout the entire clip know as “key frames”. Each key frame is a note of the masks position, rotation and depth in relation to the camera along the X, Y and Z axis.
There’s a technique called “motion tracking” where editors tell the software to keep an eye on a very specific point in each frame creating tracking data. It’s that point where special effects and color correction are placed. The effects are then "pick-whipped" through a function known as “parenting”.
Unfortunately, it isn't as simple as a one-and-done click. More often than not, having to fine tune each individual frame is required to sell the effect. This is where rotoscoping comes into play. This is much like animation.
Once the effects meet satisfactory standards, the exporting process known as "rendering" takes place. This is another painstaking step of exporting footage to later import back into the non-linear editor which each individual frame is processed and can double the amount of drive space depending on export settings.