Object ID Selector

Adobe After Effects is shipped with a num­ber of extremely capa­ble color key­ing plug-​​ins. To inter­act with my lat­est 3D shader minOb­jec­tID I required a sim­ple chroma keyer that would make it quick and sim­ple to select indi­vid­ual objects by their asso­ci­ated color ID for fur­ther pro­cess­ing as an alpha mask.

The ideal can­di­ate should ful­fill these basic require­ments and not much more:

  • Be as sim­ple and effi­cient as possible
  • Out­put a spe­cific color and not what­ever object was keyed
  • The result should be invertible
  • Be extremely pre­cise with no room for tolerance
  • Works in 8-​​, 16– and 32-​​bit color space

None of the included key­ers met all of my cri­te­ria because they either didn’t work in floating-​​point mode or were sim­ply overkill for my purposes.

I then remem­bered that I had once started to write a lit­tle chroma key­ing appli­ca­tion a few years ago and so I decided to sift through my old backup dri­ves in the hopes of find­ing this lost piece of code in order to rip out its guts and to form it into the ulti­mate Object ID selec­tor for After Effects.
For­tu­nately, I ended up find­ing the project and here I am to write about my new plug-​​in, sim­ply named Object ID Selec­tor for now.

This plug-​​in has very few para­me­ters, mak­ing it sim­ple to setup. It’s in no way an all-​​purpose key­ing solu­tion, but for select­ing IDs of objects I think this stripped down keyer is the ideal choice.

I have not yet con­sid­ered solu­tions for the alias­ing issues that might arise between over­lap­ping objects but I hope to find a prac­ti­cal answer to at least mit­i­gate the problem.

Once the plug-​​in has gone through a phase of test­ing I will prob­a­bly make the soft­ware pub­licly avail­able so it can be used in com­bi­na­tion with minOb­jec­tID.