Dan Ebberts's Expressioneering Design Guide

Sometimes it's handy to have a 3D layer only be visible when it's facing the camera. One application of this might be when you want a different image to appear when the object is facing away from the camera. There are different ways to approach this, but here we'll focus on creating an opacity expression that can detect when a camera can see the layer's front side. In that case we want the opacity

[shsh0310]

“toCompVec([0, 0, 1])[2] > 0 ? value : 0”

[MiG]

裏面レイヤーの設定。