A technical survey was published in the Journal of IEICE (February 2024 issue).
Abstract:
Toon shading provides hand-drawn anime look for 3DCG objects. Various toon shading techniques have been developed for creating hybrid animation where 3D models seamlessly blend into hand-drawn animations. This survey discusses the fundamental concepts and history of toon shading, as well as practical issues and solutions. It also examines the evolution and diversification of toon shading and related techniques, along with recent examples utilizing GPUs and AI approaches.
The Toon Shader for Anime and Beyond (in Japanese)（PDF）
Ken Anjyo
The Journal of IEICE (Institute of Electronics, Information and Communication Engineers), Vol.107 No.2, pp.167-172, 2024.02.01
Online ISSN:2188-2355, Print ISSN:0913-5693