Flux
                                A real-time physically based rendering engine written in C++ and OpenGL
                            
                        How to download and setup Flux
Open terminal and run command
                                            git clone https://github.com/JulianThijssen/Flux.git
                                        
                                        git clone is used to create a copy or clone of Flux repositories.
                                        You pass git clone a repository URL. it supports a few different network protocols and corresponding URL formats.
Also you may download zip file with Flux https://github.com/JulianThijssen/Flux/archive/master.zip
Or simply clone Flux with SSH
                                            [email protected]:JulianThijssen/Flux.git                                    
                                    If you have some problems with Flux
You may open issue on Flux support forum (system) here: https://github.com/JulianThijssen/Flux/issuesSimilar to Flux repositories
Here you may see Flux alternatives and analogs
libgdx aframe open-source-ios-apps colobot alacritty spritejs Aurora cute_headers matter-js openage openFrameworks OpenRCT2 tinyrenderer tiled mapbox-gl-native appleseed awesome-vulkan pyopencl yii2-render-many cocos2d-x CRYENGINE SFML Babylon.js ARShooter arcan boardgame.io tangram glfw allegro5 imgui