Blender Tutorial: Mouth texture replacement with the UV Warp modifier

This tutorial outlines my method for rigging mouth-replacement textures on a 3d character, using Blender's UV Warp modifier. The setup I demonstrate is perfect for lego minifig faces, Pocoyo style features, and other cool old-school and NPR looks. It can easily be adapted to other facial features or completely different uses. Hope it proves helpful to you! My starting point was Pawel Kowal's tutorial @ https://www.youtube.com/watch?v=BopkonvbCEE, where he explains how to make a paper cutout style rig. I believe Pawel is the original author of the modifier, which is now in Blender Trunk. The character is from the Quandamooka Dreaming project animations I directed in 2014, and was based on the Cookie Flex Rig by CGCookie, Inc.