Re: blackbody and daylight functions
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Blackbody works only for incandescent lights. Make it 20000K and it should look like what you posted (blue with hints of red). It'll still have red in it because all that changed from the hotter light is that correspondingly more blue was added, but red was never removed. This is why you can't get a pure blue. What you can do is drown out the red by having huge amounts of blue. Even hotter temps will emit lots of UV, but since we don't see that we'll just see it as more blue. Also, that's a crazy hot surface and probably not realistic...
In the real world filters would be applied to incandescent lights to filter out the red so we see it as more blue. Or LEDs or other non-incandescent lights are used which can generate specific frequencies of light.
Take a look at the graph in https://astronomy.swin.edu.au/cosmos/b/blackbody+radiation which shows how at 700nm the blue star is still outputting more red than the red star.
To summarize, blackbody for lights is for incandescent lights without filters. Anything else and the renderer should allow users to input colors in some other fashion, such as RGB.
On Mon, Jan 11, 2021 at 12:16 PM <chrisbrejon@...> wrote: