Godot Engine - Feature-packed 2D and 3D open source game engine.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Unity - The multiplatform game creation tools for everyone.
MakeHuman - MakeHuman is a free, open source, interactive modeling tool for creating custom 3D human characters.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Bforartists - Bforartists is a fork of Blender.