Fake game for developing shaders?

I'm wondering if anyone has suggestions or recommendations for static games / game scenes that I could use to help develop shaders without having to pay attention to an actual game.

I've been working on some shaders the last few weeks and it makes me anxious every time I load up Skyrim or some other game to develop on. I was just wondering if there were any standalone 3D scenes that I could load and test on.

Or, in another way, is there a method for loading a DX supported window with a single game screenshot for developing in? I've dabbled in things like Pillow and OpenCV, and have plenty experience in C#, C++, and Python (and some C) if that helps. Certainly not an expert, but if pointed in the right direction, I could set something up in an afternoon.

This comes up every now and then, and yes it's a good way to test shaders and profiles

Edit: Last instance was 4 years ago!

Anyway, here we go -- a tool by Ninjafada and a short guide by me:

reshade.me/forum/suggestions/476-streamlining-calibration#3842