This was the original goal of the Cornell box (https://en.wikipedia.org/wiki/Cornell_box https://en.wikipedia.org/wiki/Cornell_box, i.e. carefully measure the r

This was the original goal of the Cornell box (https://en.wikipedia.org/wiki/Cornell_box https://en.wikipedia.org/wiki/Cornell_box, i.e. carefully measure the radiosity of a simple, real-world scene and then see how closely you can come to simulating it). For realtime rendering a common thing to do is to benchmark against a known-good offline renderer (e.g. Arnold, Octane)