What do you mean by standalone renderers? There's Forge [0], which was used for Starfield. Also, there's nothing stopping you from taking a popular engine and using it as a renderer only. Remaster of Oblivion is running the original game code underneath and using Unreal Engine 5 for rendering. I assume Diablo 2 remaster did something similar because you can seamlessly switch between old and new graphics.[0] https://theforge.dev/products/the-forge/
valorzard|5 months ago