llbit
commented
5 years ago Better support for changing lighting conditions by setting time-of-day would be nice. I don't have time to work on this right now so I'm marking it as "help wanted" if anyone else wants to work on this.
Note: if the sun is below the horizon you won't get direct sunlight (except near the edge of the scene).
While chunky can render a daytime scene or a scene at night, one unavailable option to set a scene during twilight levels, so one could render a scene of daybreak or nightfall. Specifically, there are twilight levels when the sun's altitude is between 0 and -18 degrees below horizon. I have a feeling that it could be done since the sky and shadow reflection does adjust according when setting the sun's altitude to between 0 and 6 degrees above the horizon, however any value below 0 simply gets rendered as 0 degrees.
The typical definition of sunrise sunset is cut at -0.833333 degrees altitude so the sun should just outright disappear below -0.833333 degrees altitude. Civil twilight 0-6 degrees below, Nautical 6-12 degrees, Astronomical 12-18 degrees.