Julian Herrera posts a new script for After Effects called 3D to 2D ScreenSpace which takes a position in 3D space and creates a corresponding animated null in its relative 2D space.
Check out the 3D to 2D ScreenSpace for After Effects over at AEScripts here.
This script takes a 3D position and creates an animated 2D null in it’s relative 2D screen-space. Select a 3D Layer and press ‘Link’ to tie a new null to the 3D point with an expression or press ‘Bake’ to convert the expression to keyframes straight away.
This can be useful when tracking 2D elements like light flares to 3D objects in your comp.
Future versions will include the ability to enable a checkbox to “delete original” (greyed out when ‘Link’ is selected).
I looked at this way too …quickly, but doesn’t this do what the toComp() expression does?