We built Lunatics around the Blender Internal renderer, which was removed along with the game engine when they went to v2.8. Switching rendering engines would be too big an ask, so we just stuck with 2.79 (for now).
There IS a fork of the program, called "UPBGE" that incorporates both BI and the Game Engine (also removed with 2.8).
Later Blender includes the "Eevee" renderer, which I understand was based on the previous "viewport renderer" (that's also when "annotations" became separate from "grease pencil").
And the "Cycles" renderer, which is meant to be more photorealistic was retained.
But they junked "Blender Internal". I understand it had a lot of "technical debt". And the Blender Game Engine I think was considered to be out of scope and not competitive with other game engines, so they dropped that.
There are also 3rd party renderers. I haven't tried them, myself, but I hear good things about them from time to time.
One of particular interest to me is "BEER" the "Blender Extended Expressive Renderer" which is explicitly designed for NPR3D work, and it's successor (I think), called "Malt".
I might give those a go before long. Maybe next year.
It occurs to me to wonder if UPBGE or some other package of BI can be used for rendering from later versions of Blender? 🤔
UPBGE:
https://upbge.org
BNPR - BEER & MALT:
https://github.com/bnpr
#Blender3D #NPR3D