Look at the two attached imagea. I have white lumber, but when using
radiosity (1st image), the white lumber glows and simply emits too much
reflected indirect light. The 2nd image shows the same scene without
radiosity.

is there a way to reduce the amount of reflected indirect light?


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On 30-4-2018 7:12, Sven Littkowski wrote:
> Look at the two attached imagea. I have white lumber, but when using
> radiosity (1st image), the white lumber glows and simply emits too much
> reflected indirect light. The 2nd image shows the same scene without
> radiosity.
> 
> is there a way to reduce the amount of reflected indirect light?
> 

What is the finish{} of your lumber texture? I guess all is there.

-- 
Thomas

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On 04/30/2018 01:12 AM, Sven Littkowski wrote:
> Look at the two attached imagea. I have white lumber, but when using
> radiosity (1st image), the white lumber glows and simply emits too much
> reflected indirect light. The 2nd image shows the same scene without
> radiosity.
> 
> is there a way to reduce the amount of reflected indirect light?

seriously!?! lol-lol-lol ... sorry couldn't resist

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Sven Littkowski <I### [at] SvenLittkowskiname> wrote:

> is there a way to reduce the amount of reflected indirect light?


http://www.povray.org/documentation/view/3.6.0/270/

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Am 30.04.2018 um 07:12 schrieb Sven Littkowski:
> Look at the two attached imagea. I have white lumber, but when using
> radiosity (1st image), the white lumber glows and simply emits too much
> reflected indirect light. The 2nd image shows the same scene without
> radiosity.
> 
> is there a way to reduce the amount of reflected indirect light?


* MAKE SURE you're not just using an overly bright light source and/or
environment (sky sphere, background, whatever)! Turning on radiosity in
a scene that has a lot of bright surfaces WILL typically increase the
overall apparent brightness -- which is not radiosity's fault, but
rather that of the "poor man's" alternative, the `ambient` parameter,
which is usually set to a value far too dim for white surfaces.(*)

(* BTW, technically the `ambient` parameter shouldn't be set according
to the material itself, but rather according to the environment of the
particular object(s) that will be set to this material.)


If that isn't the issue, ...

- Make sure you're not using `emission` in the material finish.

- Make sure you're either using `#version 3.7` or later, or you're using
`ambient_light 0` in the global settings, or you're using `ambient 0` in
the material finish.

- Make sure your pigment is not unrealistically bright. Real-life
"white" paints are typically around 0.95, real-life "white" woods are
probably closer to 0.6.

- Make sure your `diffuse` setting is not unrealistically high,
especially in combination with `reflection`. When using `fresnel`, it is
ok to set both diffuse and reflection as high as 1.0 (presuming you're
properly controlling the brightness via the pigment); otherwise, the
/sum/ of the two should not exceed 1.0.


Also -- but this should be self-evident, ...

- Make sure you're not using an excessively high `brightness` value in
the radiosity settings ("excessively high" being anything noticeably
higher than 1.0).

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Sven Littkowski <I### [at] SvenLittkowskiname> wrote:
> Look at the two attached imagea. I have white lumber, but when using
> radiosity (1st image), the white lumber glows and simply emits too much
> reflected indirect light. The 2nd image shows the same scene without
> radiosity.
>
> is there a way to reduce the amount of reflected indirect light?

Hi Sven,

First - you need a background - a sky_sphere or a simple color.

Second - you use a phong_size of 0.5. I recommend a number larger than 100.

Third - you should reduce your standard diffuse to less than 2 - and rise
light_source accordingly. Personally I use this combination for a first shot -

#declare lights = <-80000,50000,-50000>;
light_source {
        lights,
        color srgb <2.42,2.23,1.87>
}

sky_sphere {
        pigment {
                function {max (min (y, 1), 0)}
                color_map {
                        [0        srgb <212,221,239>/255]
                        [0.1029   srgb <219,229,244>/255]
                        [0.1512   srgb <233,241,250>/255]
                        [0.1949   srgb <223,239,252>/255]
                        [0.2444   srgb <201,227,252>/255]
                        [0.2921   srgb <180,213,250>/255]
                        [0.3732   srgb <144,180,239>/255]
                        [0.4255   srgb <137,172,235>/255]
                        [0.7067   srgb <97,126,198>/255]
                        [0.774    srgb <92,119,190>/255]
                        [0.8275   srgb <88,114,185>/255]
                        [0.885    srgb <85,111,180>/255]
                        [0.9425   srgb <82,107,175>/255]
                        [1        srgb <79,103,170>/255]
                }
        }
}

Norbert

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Le 18-04-30 à 01:12, Sven Littkowski a écrit :
> Look at the two attached imagea. I have white lumber, but when using
> radiosity (1st image), the white lumber glows and simply emits too much
> reflected indirect light. The 2nd image shows the same scene without
> radiosity.
> 
> is there a way to reduce the amount of reflected indirect light?
> 
> 
> ---
> Diese E-Mail wurde von AVG auf Viren geprüft.
> http://www.avg.com
> 

Your diffuse parameter looks to be set way to high. diffuse 1 is 
normally NOT OK. Try using the default value.

Make sure that you don't have any ambient nor emission set in your 
finish. If in doubt, explicitly set them to zero. With version 3.7, 
ambient should be turned OFF automatically when using radiosity, but 
it's not the case if you are using version 3.6; or less. Most includes 
locally use version 3.5, and this may play some tricks on you.

Don't change brightness from it's default in the radiosity block.

If you use reflection, try using a smaller value.

Try a darker background.

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