C++ header-only library that simulates GLSL math
Lightweight and modular C++11 graphics middleware for data and games
Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
A performant, flexible, and easy-to-use real-time 3D rendering engine
A really simple (following K.I.S.S statement) ray tracing project.
3D game engine for C and C++
Pear3DEngine is a modern and modular 3D development framework
PixelLight is a cross-platform application framework
A 3D rendering / entity engine