There’s a (very reasonable at this time, I think) emphasis in this high-preformance day and evening lighting on trying to match natual brightness and spectrum.
Have you come accross any good data or models for late-day/early dusk?
I ask because while there’s a lot of good data and models for mid-day solar illumination, I don’t know enough to know how much to trust them towards the end of the day (which I suspect is not really the designed use case), nevermind stuff after sunset—and there’s over an hour between sunset and astronomical dusk.
(But yes, for midday… lots of models to choose from. The SMARTS model seems like a good choice. Good-enough accuracy, covers spectrum from 280–4000nm, easy setup, and has relatively few inputs and outputs to worry about. Big comprimise is that the diffuse illumination is treated as uniform, and it doesn’t do clouds.)
This is a good question. I have not looked, and the closest thing I have done is to measure the color temperature and intensity according to my camera for direct sunlight just before sunset (seems to be about 2700K, 1900lx).
I would think that you could get a decent estimate using SMARTS if you adapted the input file to a ray going through a lot more atmosphere, but I’m not sure. I haven’t looked at the code and it might do something like make approximations that only work for short path lengths or low optical densities or something.
There’s a (very reasonable at this time, I think) emphasis in this high-preformance day and evening lighting on trying to match natual brightness and spectrum.
Have you come accross any good data or models for late-day/early dusk?
I ask because while there’s a lot of good data and models for mid-day solar illumination, I don’t know enough to know how much to trust them towards the end of the day (which I suspect is not really the designed use case), nevermind stuff after sunset—and there’s over an hour between sunset and astronomical dusk.
(But yes, for midday… lots of models to choose from. The SMARTS model seems like a good choice. Good-enough accuracy, covers spectrum from 280–4000nm, easy setup, and has relatively few inputs and outputs to worry about. Big comprimise is that the diffuse illumination is treated as uniform, and it doesn’t do clouds.)
This is a good question. I have not looked, and the closest thing I have done is to measure the color temperature and intensity according to my camera for direct sunlight just before sunset (seems to be about 2700K, 1900lx).
I would think that you could get a decent estimate using SMARTS if you adapted the input file to a ray going through a lot more atmosphere, but I’m not sure. I haven’t looked at the code and it might do something like make approximations that only work for short path lengths or low optical densities or something.