Unreal Engine
Unreal Engine documentation
Unreal Engine video channel
Foundations of Game Engine Development 1 & 2, Eric Lengyel
Game Engine Architecture, Jason Gregory
Real-time Rendering, by Tomas Akenine-Möller, Eric Haines, Naty Hoffman, Angelo Pesce, Michał Iwanicki, and Sébastien Hillaire
Ray Tracing Gems: High-Quality and Real-Time Rendering with DXR and Other APIs, edited by Eric Haines and Tomas Akenine-Möller
Physically Based Rendering: From Theory To Implementation, Matt Pharr, Wenzel Jakob, and Greg Humphreys
Ray Tracing in One Weekend, Peter Shirley
An Introduction to Ray Tracing, edited by Andrew Glassner
Ray Tracing Resources
Graphics Programming Weekly blog, by Jendrik Illner
Rendering, by Sung-eui Yoon
The CG Tutorial, by Mark Kilgard and Randima Fernando
Blender 3D Creation Suite
Google Poly
Shadertoy, by Íñigo Quílez and Pol Jeremias
Articles and code tutorials, by Íñigo Quílez
The Book of Shaders (GLSL), by Patricio Gonzalez Vivo and Jen Lowe
Computer Graphics from Scratch, by Gabriel Gambetta
Technically Art, by Harry Alisavakis