Those are massive engines, with plenty of features I don't need. I can't rely on those engines because they're just made to make full fledged games, and often they force many paradigm or methods of working I don't really like. Not to mention the freedom thing, and how those engines are supported.
> 3D rendering doesn't really get any more simple than a blank OpenGL context window.
OpenGL is pretty low level. It's a bare standard bridge to make use of a GPU. What I mean is that there are either very high level engines, or a very low level graphics API, which requires a lot of work if you want to make anything decent with it. There are things like glfw glew, but nothing like a very simple to use 3D rendering library, that just does the bare minimum, like a camera, quaternions, some text rendering, inputs, offers some simpler access to what opengl has to offer, etc.
3D engines are always being made obsolete. Except irrlicht and ogre3d, which are still fat enough in my opinion, there are no general-purpose, light 3D renderer, that are not necessarily trying to do it all. This kind of engine might serve as a thin wrapper to opengl to just avoid the work with the high quantity of opengl calls.
I've used libgdx[1] before, it's still fully supported and is being developed further. It is still fairly low level,but it has just enough things in it to make things like draw calls, vbos and shader management easier. That being said, I still ended up writing my own shaders for lighting and shadows, as far as I know there isn't anything in between libraries like this and huge engines like Unity/UE.
> 3D rendering doesn't really get any more simple than a blank OpenGL context window.
OpenGL is pretty low level. It's a bare standard bridge to make use of a GPU. What I mean is that there are either very high level engines, or a very low level graphics API, which requires a lot of work if you want to make anything decent with it. There are things like glfw glew, but nothing like a very simple to use 3D rendering library, that just does the bare minimum, like a camera, quaternions, some text rendering, inputs, offers some simpler access to what opengl has to offer, etc.
3D engines are always being made obsolete. Except irrlicht and ogre3d, which are still fat enough in my opinion, there are no general-purpose, light 3D renderer, that are not necessarily trying to do it all. This kind of engine might serve as a thin wrapper to opengl to just avoid the work with the high quantity of opengl calls.