This is correct, however, not everything is lit by sunlight, especially onset in the motion picture industry, where solid state lighting and its narrow band irradiance sources, e.g. led lights or led walls, are prevalent. Those emission sources induce a lot of unexpected appearance problems, e.g. metameric failures that RGB rendering cannot possibly solve. Our spectral renderer, i.e. Manuka [1], was specifically designed to address those issues whilst imaging with a virtual motion picture camera.
One recent example I have in mind is The Batman (2022): There are sequences/shots lit with high-pressure sodium lights (HPS), those have a flat spectrum with spikes between 500 and 600nm, the appearance of objects lit under them is very specific and can only be accurately reproduced with a spectral renderer such as Manuka, Mitsuba [2] or Art [3].
- [1] https://www.wetafx.co.nz/research-and-tech/technology/manuka...