Am 18.03.2018 um 22:02 schrieb Kenneth:

> Let me re-word that, so it hopefully makes better sense...
> 
> Given:
> radiosity{brightness 1.0}
> light_source{rgb .7}
> object{... pigment{rgb <.3,.5,.7> finish{diffuse 1.0}}
> 
> Does the 'automatic balancing' keep the object surface's DIFFUSE color from
> exceeding .7*<.3,.5,.7> (as if NO radiosity is used)--depending of course on the
> angle-of-incidence of the light source hitting the object? Or does my diffuse
> setting need to be manually reduced, to keep the color from washing out to, say,
> 
>        .7*<.3 + 1.0,.5 + 1.0,.7 + 1.0>  or maybe  (1.0 + .7)*<.3,.5,.7>
> 
> .....DUE TO THE ADDITION OF RADIOSITY LIGHT. Or am I still clueless about what
> 'automatic balancing' means? :-O

If you disable radiosity, your result image will have

    .7*Fc*<.3,.5,.7>

where Fc is a scalar (depending on angle of incidence and such stuff),
i.e. colour neutral.

If you enable radiosity and the sky colour is grey with a brightness of
.5, your result image will have:

    .7*Fc*<.3,.5,.7> + .5*Fr*<.3,.5,.7>

where Fr is also a scalar (again depending on angle of incidence and
such stuff), i.e. colour neutral; so in total you'll get:

    (.7*Fc+.5*Fr) * <.3,.5,.7>

So no washing out there - just more brightness.

Things get different if your sky sphere isn't colour neutral, but the
same would be true for a non-colour-neutral point light source.


But maybe instead of your colours getting "washed out", what you really
mean is that your colours are getting "burned" - the effect that you get
when one or two colour components exceed the dynamic range of the LDR
output file format and is thus clipped, effectively desaturating the colour.

If that is what you get, the proper solution is to tune down the
brightness of /both/ the sun and the sky (which, as noted before, isn't
the same as tuning down the radiosity brightness setting).

Post a reply to this message