POV-Ray : Newsgroups : povray.general : strange problem with srgb color in light_source : Re: strange problem with srgb color in light_source Server Time
6 Dec 2022 09:59:48 EST (-0500)
  Re: strange problem with srgb color in light_source  
From: Kenneth
Date: 1 Apr 2021 09:35:00
Message: <web.6065ca19a9b7c959d98418916e066e29@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> If I remember correctly, Clipka always hammered on:
> - NEVER do this: srgb <.5, .3, .7>*50000;
> - ALWAYS do this: srgb <.5*50000, .3*50000, .7*50000>;

Unfortunately, that does not work either; the light is still blown-out and super
Using #debug,
srgb <.5*50000, .3*50000, .7*50000> =
<31568424960.000, 9264402432.000, 70787989504.000>

As Cousin Ricky's #debug analysis shows, it should be:

C3 = <10702.1, 3661.9, 22399.4>

So it seems that there are only two ways to get this srgb-multiplication scheme
to work successfully:

1) To pre-#declare the color as srgb <.5,.3,.7>, and then to plug that into the
light as  TEMP_COLOR*50000

2) to actually use the complex rgb-to-srgb conversion formula itself in the
light (or srgb-to-rgb?), when specifying the color.

I prefer option 1)-- it's so much easier, even if I don't fully understand why
it works  ;-)

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