The built-in 3D implementation in After Effects is nowhere near as deep as a dedicated 3D program. However, it does have a few good tricks up its sleeve. On is Adjustment Lights, where you can determine which layers receive a specific light. This is akin the lighting sets in more sophisticated 3D programs.
The built-in 3D implementation in After Effects is nowhere near as deep as a dedicated 3D program (such as CINEMA 4D Lite, which is now bundled with After Effects). However, it does have a few good tricks up its sleeve. On is Adjustment Lights, where you can determine which layers receive a specific light. This is akin the lighting sets in more sophisticated 3D programs.
3D Lights in After Effects usually illuminate all 3D layers in a composition, regardless of layer stacking order. However, if you enable the Adjustment Layer switch for a 3D Light, it will now illuminate just the 3D layers that appear below it in the Timeline panel stack, just as a 2D Adjustment Layer effects layers underneath it. Since 3D layers otherwise ignore their layer stacking order – distance from the camera, rather than layer number, determines how they are composited – you can selectively drag 3D layers above or below an Adjustment Light to determine whether or not they are illuminated by that light.
This is demonstrated in the After Effects Hidden Gems Weekly movie for the week of July 20, 2015 at bit.ly/ae-hg, including an approach using negative light Intensity to selectively subtract illumination from 3D layers. That movie also demonstrates other important parameters that affect illumination such as Light Falloff as well as Diffuse and Specular Intensity. After the week of July 20, this movie will only be visible to lynda.com subscribers (along with all of the other gems to date). If you’re not already a subscriber, you can get a 10-day free trial before your credit card is billed by using the link http://www.lynda.com/go/ChrisAndTrish.