armory VS ShaderGen

What's really missing is an open source "bring your own engine and asset pipeline" editor tool. Game editors have pretty much arrived at the Unity data model and editor workflow (game object outliner to the left, scene view in the middle, property panel on the right, asset panel at the bottom, plus custom panels).

The Unity Editor and asset pipeline is hackable enough to use it as editor for another engine, I did that in the past as "proof of concept" and it definitely works, but is most likely a legal minefield.

Blender is also definitely hackable enough to serve that role (see: https://armory3d.org/) (again I did something similar in the past with Maya, it kinda works, but this wasn't very popular with artists because they were overwhelmed by the UI).

There are two primary contenders to replace the BGE. One is Armory3D (https://armory3d.org/) It has a ton of potential, and outputs to multiple formats including web. But it's a one-developer show and it's been really inconsistent. I taught a class on prototyping 3D games with it, but updates are slow and inconsistent, as is the documentation. Too bad, because it's a promising project, with a blueprints-like visual system and Haxe (basically an open-source actionscript) as the programming language.

https://armory3d.org/features is more of a game engine than just a 3d renderer but not as advanced as unity or unreal in certain aspects. One can write game logic in c/c++/rust -- https://github.com/armory3d/armory/wiki/wasm

Website

Armory3D is also interesting, not a fork of the original BGE AFAIK but integrates with Blender.

Armory3d

I don't know what it's worth, but Armory3D is also an engine built with Blender : https://armory3d.org/

Another project is ShaderGen [0] which enables writing C# that can run on the GPU as well as on the CPU.

And there is a practical example implementing raytracing [1].

[0] https://github.com/mellinoe/shadergen

[1] https://github.com/mellinoe/veldrid-raytracer