On 2/23/2018 8:18 AM, Alain wrote:
> The 3 lumen looks a little to bright.
> Can you post the 1 lumen image?
> 
> Also, the sun position is not the same for the two images. It mover by 
> around 40°.

Here it is with RGB instead of SRGB, and 1 lumens.

https://i.imgur.com/AcGBbla.jpg

As you can see, it is pretty dim and lifeless.


Mike

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Le 18-02-24 à 11:07, Mike Horvath a écrit :
> On 2/23/2018 8:18 AM, Alain wrote:
>> The 3 lumen looks a little to bright.
>> Can you post the 1 lumen image?
>>
>> Also, the sun position is not the same for the two images. It mover by 
>> around 40°.
> 
> Here it is with RGB instead of SRGB, and 1 lumens.
> 
> https://i.imgur.com/AcGBbla.jpg
> 
> As you can see, it is pretty dim and lifeless.
> 
> 
> Mike

Slightly dimmer, not prety dim, than the 2 lumens but not lifeless on my 
monitor. Maybe your monitor is set to dim...
Definitively better than the 3 lumens version.

Set assumed_gamma 1
When using lightsys, always use RGB for the lights. lightsys is made to 
return values in the rgb colour space, not the srgb one. You may use 
srgb for the textures.


Alain

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On 24-2-2018 17:07, Mike Horvath wrote:
> On 2/23/2018 8:18 AM, Alain wrote:
>> The 3 lumen looks a little to bright.
>> Can you post the 1 lumen image?
>>
>> Also, the sun position is not the same for the two images. It mover by 
>> around 40°.
> 
> Here it is with RGB instead of SRGB, and 1 lumens.
> 
> https://i.imgur.com/AcGBbla.jpg
> 
> As you can see, it is pretty dim and lifeless.
> 

On my screen it looks right.

I often use CIE.inc myself, maybe in a little different way than you do. 
This is an example of how I define my sunlight in a scene:

//start code -----------------------------------
#include "CIE.inc"
#if (Fog)
   #local Intensity    = 5;
#else
   #local Intensity    = 3;
#end
//Sun's temperature (Kelvin): 2800=red; 7500=blue white
#declare SunColor     = Blackbody(6500)*Intensity;
#declare SunPosition  = <0, 0, -2>*10e4;
#declare SunDis       = vlength(SunPosition)*2/215;
#declare Sun_alt      = 60;
#declare Sun_azm      = -115;

#if (Area)
   #debug "\nUsing an area_light for the Sun.\n"
   light_source{
     <0, 0, 0>
     color SunColor
     area_light
     SunDis*x, SunDis*z, // lights spread out (x * z)
     4, 4                // total lights in grid (4x*4z = 16 lights)
     adaptive 1          // 0,1,2,3...
     area_illumination on  // full area diffuse and specular
     jitter              // adds random softening of light
     circular            // make the shape of the light circular
     orient              // orient light
     translate SunPosition
     rotate Sun_alt*x
     rotate Sun_azm*y
     parallel
     point_at <0, 0, 0>
     media_interaction on
     media_attenuation off
   }
#else
   light_source {
     <0, 0, 0>
     color rgb SunColor
     translate SunPosition
     rotate Sun_alt*x
     rotate Sun_azm*y
     parallel
     point_at <0, 0, 0>
     media_interaction on
     media_attenuation off
   }
#end
//end code -----------------------------------


-- 
Thomas

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Le 18-02-25 à 02:53, Thomas de Groot a écrit :
> On 24-2-2018 17:07, Mike Horvath wrote:
>> On 2/23/2018 8:18 AM, Alain wrote:
>>> The 3 lumen looks a little to bright.
>>> Can you post the 1 lumen image?
>>>
>>> Also, the sun position is not the same for the two images. It mover 
>>> by around 40°.
>>
>> Here it is with RGB instead of SRGB, and 1 lumens.
>>
>> https://i.imgur.com/AcGBbla.jpg
>>
>> As you can see, it is pretty dim and lifeless.
>>
> 
> On my screen it looks right.
> 
> I often use CIE.inc myself, maybe in a little different way than you do. 
> This is an example of how I define my sunlight in a scene:
> 
> //start code -----------------------------------
> #include "CIE.inc"
> #if (Fog)
>    #local Intensity    = 5;
> #else
>    #local Intensity    = 3;
> #end
> //Sun's temperature (Kelvin): 2800=red; 7500=blue white
> #declare SunColor     = Blackbody(6500)*Intensity;
> #declare SunPosition  = <0, 0, -2>*10e4;
> #declare SunDis       = vlength(SunPosition)*2/215;
> #declare Sun_alt      = 60;
> #declare Sun_azm      = -115;
> 
> #if (Area)
>    #debug "\nUsing an area_light for the Sun.\n"
>    light_source{
>      <0, 0, 0>
>      color SunColor
>      area_light
>      SunDis*x, SunDis*z, // lights spread out (x * z)

A better, more descriptive, name would be "SunDiam"

>      4, 4                // total lights in grid (4x*4z = 16
lights)

This will actually use a 5 by 5 array...

>      adaptive 1          // 0,1,2,3...

...and start with a 3 by 3 one.
With adaptive, you can use a much larger value, like 17 or 33 without 
increasing the render time much.
adaptive 0 DON'T turn the feature off, but start with a 2 by 2 array.

>      area_illumination on  // full area diffuse and specular
>      jitter              // adds random softening of light

Makes the penumbra grainy if using a sparse array.

>      circular            // make the shape of the light circular
>      orient              // orient light
>      translate SunPosition
>      rotate Sun_alt*x
>      rotate Sun_azm*y
>      parallel
>      point_at <0, 0, 0>
>      media_interaction on
>      media_attenuation off
>    }
> #else
>    light_source {
>      <0, 0, 0>
>      color rgb SunColor
>      translate SunPosition
>      rotate Sun_alt*x
>      rotate Sun_azm*y
>      parallel
>      point_at <0, 0, 0>
>      media_interaction on
>      media_attenuation off
>    }
> #end
> //end code -----------------------------------
> 
> 

Using adaptive, you need larger arrays to get all the benefit. Some 
suggested sizes in relation with the adaptive steps values :
adaptive 0 (0 initial subdivisions)  at least 5 by 5 (2 steps)
adaptive 1 (1 initial subdivisions)  at least 9 by 9 (3 steps)
adaptive 2 (2 initial subdivisions)  at least 17 by 17 (4 steps)
adaptive 3 (3 initial subdivisions)  at least 33 by 33 (5 steps)

You can always use larger arrays to get smoother results.

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On 26-2-2018 1:03, Alain wrote:
> Le 18-02-25 à 02:53, Thomas de Groot a écrit :
>> On 24-2-2018 17:07, Mike Horvath wrote:
>>> On 2/23/2018 8:18 AM, Alain wrote:
>>>> The 3 lumen looks a little to bright.
>>>> Can you post the 1 lumen image?
>>>>
>>>> Also, the sun position is not the same for the two images. It mover 
>>>> by around 40°.
>>>
>>> Here it is with RGB instead of SRGB, and 1 lumens.
>>>
>>> https://i.imgur.com/AcGBbla.jpg
>>>
>>> As you can see, it is pretty dim and lifeless.
>>>
>>
>> On my screen it looks right.
>>
>> I often use CIE.inc myself, maybe in a little different way than you 
>> do. This is an example of how I define my sunlight in a scene:
>>
>> //start code -----------------------------------
>> #include "CIE.inc"
>> #if (Fog)
>>    #local Intensity    = 5;
>> #else
>>    #local Intensity    = 3;
>> #end
>> //Sun's temperature (Kelvin): 2800=red; 7500=blue white
>> #declare SunColor     = Blackbody(6500)*Intensity;
>> #declare SunPosition  = <0, 0, -2>*10e4;
>> #declare SunDis       = vlength(SunPosition)*2/215;
>> #declare Sun_alt      = 60;
>> #declare Sun_azm      = -115;
>>
>> #if (Area)
>>    #debug "\nUsing an area_light for the Sun.\n"
>>    light_source{
>>      <0, 0, 0>
>>      color SunColor
>>      area_light
>>      SunDis*x, SunDis*z, // lights spread out (x * z)
> 
> A better, more descriptive, name would be "SunDiam"
> 
>>      4, 4                // total lights in grid (4x*4z = 16
lights)
> 
> This will actually use a 5 by 5 array...
> 
>>      adaptive 1          // 0,1,2,3...
> 
> ...and start with a 3 by 3 one.
> With adaptive, you can use a much larger value, like 17 or 33 without 
> increasing the render time much.
> adaptive 0 DON'T turn the feature off, but start with a 2 by 2 array.
> 
>>      area_illumination on  // full area diffuse and specular
>>      jitter              // adds random softening of light
> 
> Makes the penumbra grainy if using a sparse array.
> 
>>      circular            // make the shape of the light circular
>>      orient              // orient light
>>      translate SunPosition
>>      rotate Sun_alt*x
>>      rotate Sun_azm*y
>>      parallel
>>      point_at <0, 0, 0>
>>      media_interaction on
>>      media_attenuation off
>>    }
>> #else
>>    light_source {
>>      <0, 0, 0>
>>      color rgb SunColor
>>      translate SunPosition
>>      rotate Sun_alt*x
>>      rotate Sun_azm*y
>>      parallel
>>      point_at <0, 0, 0>
>>      media_interaction on
>>      media_attenuation off
>>    }
>> #end
>> //end code -----------------------------------
>>
>>
> 
> Using adaptive, you need larger arrays to get all the benefit. Some 
> suggested sizes in relation with the adaptive steps values :
> adaptive 0 (0 initial subdivisions)  at least 5 by 5 (2 steps)
> adaptive 1 (1 initial subdivisions)  at least 9 by 9 (3 steps)
> adaptive 2 (2 initial subdivisions)  at least 17 by 17 (4 steps)
> adaptive 3 (3 initial subdivisions)  at least 33 by 33 (5 steps)
> 
> You can always use larger arrays to get smoother results.

Thanks Alain, well spotted indeed. I always unthinkingly use the set up 
as is. ;-)

-- 
Thomas

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On 2/24/2018 12:23 PM, Alain wrote:
> Le 18-02-24 à 11:07, Mike Horvath a écrit :
>> On 2/23/2018 8:18 AM, Alain wrote:
>>> The 3 lumen looks a little to bright.
>>> Can you post the 1 lumen image?
>>>
>>> Also, the sun position is not the same for the two images. It mover 
>>> by around 40°.
>>
>> Here it is with RGB instead of SRGB, and 1 lumens.
>>
>> https://i.imgur.com/AcGBbla.jpg
>>
>> As you can see, it is pretty dim and lifeless.
>>
>>
>> Mike
> 
> Slightly dimmer, not prety dim, than the 2 lumens but not lifeless on my 
> monitor. Maybe your monitor is set to dim...
> Definitively better than the 3 lumens version.
> 
> Set assumed_gamma 1
> When using lightsys, always use RGB for the lights. lightsys is made to 
> return values in the rgb colour space, not the srgb one. You may use 
> srgb for the textures.
> 
> 
> Alain

My monitor is set to "SRGB". Dunno what it should be set to.


Mike

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Le 18-02-26 à 17:51, Mike Horvath a écrit :
> On 2/24/2018 12:23 PM, Alain wrote:
>> Le 18-02-24 à 11:07, Mike Horvath a écrit :
>>> On 2/23/2018 8:18 AM, Alain wrote:
>>>> The 3 lumen looks a little to bright.
>>>> Can you post the 1 lumen image?
>>>>
>>>> Also, the sun position is not the same for the two images. It mover 
>>>> by around 40°.
>>>
>>> Here it is with RGB instead of SRGB, and 1 lumens.
>>>
>>> https://i.imgur.com/AcGBbla.jpg
>>>
>>> As you can see, it is pretty dim and lifeless.
>>>
>>>
>>> Mike
>>
>> Slightly dimmer, not prety dim, than the 2 lumens but not lifeless on 
>> my monitor. Maybe your monitor is set to dim...
>> Definitively better than the 3 lumens version.
>>
>> Set assumed_gamma 1
>> When using lightsys, always use RGB for the lights. lightsys is made 
>> to return values in the rgb colour space, not the srgb one. You may 
>> use srgb for the textures.
>>
>>
>> Alain
> 
> My monitor is set to "SRGB". Dunno what it should be set to.
> 
> 
> Mike

Same thing here. sRGB is correct for the monitor.

But, what about the brightness and contrast settings? Normally, contrast 
should be set high (100%) and brightness relatively low (<30%). 
Brightness is to be adjusted for the ambient lighting level of the room, 
but not the contrast.
A low contrast makes your display washed out and generally lifeless.
If you have a saturation setting for the monitor, set it around 50% to 
start.

Next, you have the file gamma and display gamma to adjust. File gamma 
can be set from 1 to 2.2 or srgb, or something else if you want to. 
Display gamma should be the same as your actual gamma setting for the 
monitor : SRGB in your case.

Post a reply to this message

On 2/27/2018 8:38 PM, Alain wrote:
> Same thing here. sRGB is correct for the monitor.
> 
> But, what about the brightness and contrast settings? Normally, contrast 
> should be set high (100%) and brightness relatively low (<30%). 
> Brightness is to be adjusted for the ambient lighting level of the room, 
> but not the contrast.
> A low contrast makes your display washed out and generally lifeless.
> If you have a saturation setting for the monitor, set it around 50% to 
> start.
> 
> Next, you have the file gamma and display gamma to adjust. File gamma 
> can be set from 1 to 2.2 or srgb, or something else if you want to. 
> Display gamma should be the same as your actual gamma setting for the 
> monitor : SRGB in your case.


I just checked on my phone, and it looks just as bad. So, I don't know 
what's wrong with your monitor.


Mike

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On 2/25/2018 2:53 AM, Thomas de Groot wrote:
> I often use CIE.inc myself, maybe in a little different way than you do. 
> This is an example of how I define my sunlight in a scene:
> 
> #if (Fog)
>    #local Intensity    = 5;
> #else
>    #local Intensity    = 3;
> #end
> //Sun's temperature (Kelvin): 2800=red; 7500=blue white
> #declare SunColor     = Blackbody(6500)*Intensity;
> #declare SunPosition  = <0, 0, -2>*10e4;
> #declare SunDis       = vlength(SunPosition)*2/215;
> #declare Sun_alt      = 60;
> #declare Sun_azm      = -115;
> 

This is much lighter, thanks. But maybe a little too white. I want a bit 
more color, but don't have an atmosphere to filter the sun's rays.


Mike

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On 28-2-2018 6:17, Mike Horvath wrote:
> On 2/25/2018 2:53 AM, Thomas de Groot wrote:
>> I often use CIE.inc myself, maybe in a little different way than you 
>> do. This is an example of how I define my sunlight in a scene:
>>
>> #if (Fog)
>>    #local Intensity    = 5;
>> #else
>>    #local Intensity    = 3;
>> #end
>> //Sun's temperature (Kelvin): 2800=red; 7500=blue white
>> #declare SunColor     = Blackbody(6500)*Intensity;
>> #declare SunPosition  = <0, 0, -2>*10e4;
>> #declare SunDis       = vlength(SunPosition)*2/215;
>> #declare Sun_alt      = 60;
>> #declare Sun_azm      = -115;
>>
> 
> This is much lighter, thanks. But maybe a little too white. I want a bit 
> more color, but don't have an atmosphere to filter the sun's rays.
> 

Just play with the Intensity value :-)

Intensity=1; would be the normal use. I always adapt according to the 
scene I am working on.

-- 
Thomas

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