The videos are generated using a Keyframe that is either painted by hand or have edited with some specific style. Using 3D Neural Style Transfer, it's possible to take the information from 1 frame and apply to the entire animation.
📖 Published paper about the technique:
📖 Suplementary Material:
👨🎓 Researched and implemented by Daniel Sýkora for the Department of Computer Graphics and Interaction,Faculty of Electrical Engineering, Czech Technical University in Prague and presented on the SIGGRAPH 2019 conference.: