That's a good question!
We made the training data for this using a physically based renderer (i.e, Cycles in Blender).
For non-photorealistic art, there are way too many ways in which artists communicate lighting (even in sketch, which is different from pixel-art / video game, there are at least a couple of ways (a) solid shading (b) hatching).
I'm not sure how to extend our methodology (synthetic data in 3D modeling software + train model) to these settings.
Ooh, I didn't know about Myst-style games. I'll definitely check them out!
