All depends on your need for quality and finesse of the basic techniques. Your ability to drive AE will determine the level of class your effect has, might just be a dumb cliché if you’re not careful.
Creating the halo object is easy. Importing it is easy. Tracking it to your character is fairly simple if you know how to do rotation and corner pinning while tracking (and throughfully provided something to track in your makeup or costume designs). Masking the halo object so it passes behind the head and interacts realistically with other objects in your scenes is tedious but fairly simple. Applying glows and radiating light effects is a bit more complex but all those other steps must be completed first. You will be using CC Light Burst or CC Light Rays so visit Cycore and download the documentation for their effects. A bit confusing at first so give yourself lots of time to work on the details.
To elevate your illusion to the next level of cool, you should have included practical lighting effects in your scenes that suggest the presence of a light producing object floating over the character’s head.
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