Flash Layer Mask Tutorial Using iRobot

Hey, I don’t know if anyone here can help me, but I saw this really cool tutorial of a Flash layer mask using a picture a robot from iRobot on the internet about a month ago, but now I can’t find it :frowning: The tutorial was using a layer mask to simulate energy or light passing by the robot. It used a white bar passing up verticly on the photo, and a layer mask to restrict where the white bar was visible. It was a really simple, yet cool effect. If anyone has seen this turorial PLEASE let me know the URL. Thanks!