Am 12.12.2011 22:37, schrieb Dre:
> Awesome!

Thanks.

>How did you get that real nice blue light to work??

Well, the construction of the ceiling, the dome and the whole lighting 
is so simple that I'm almost ashamed of it ;)

It is really just a clipped_by sphere and a torus (both with a radial 
texture and emission) and one spotlight.
The spotlight simulates two things at once:
- the "daylight lamp" that would simulate the sun within the arboretum 
and is currently close to zenith.
- the "light tubes" surrounding the dome.
The radius of the spotlight matches exactly the dome radius and the 
falloff is adjusted to match the top of the port and starboard window 
walls. It is yellow/red to compensate for the blue dome color and the 
blue tint produced by radiosity. So we get an average white daylight 
condition under the dome and a slightly bluish tint at the outside due 
the falloff of the spotlight.

   light_source { <0,10,0>  rgb <0.90, 0.85, 0.75>*5
     spotlight point_at <0,0,0> radius 48 falloff 66
     area_light x*0.67 z*0.67 5,5 adaptive 2 circular orient
     fade_power 2 fade_distance FD*2
     projected_through {Ceiling}
   }

This together with moderate radiosity settings

   radiosity {
     pretrace_start 0.08
     pretrace_end   2/max(image_width,image_height)
     count 250
     nearest_count 10
     error_bound 0.45
     recursion_limit 1
     low_error_factor 0.5
     gray_threshold 0
     minimum_reuse 0.015
     brightness 1.0
     adc_bailout 0.01/2
     always_sample off
     normal off
   }

produced the original image at 1920x1080 pixel within 24 hours - and I 
consider this also as quite moderate given the incredible amount of 
grass blades, leaves and petals ;)

-Ive

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Ive <ive### [at] lilysoftorg> wrote:
> Inside the arboretum...

This is wonderful! Beautifully done sir, as always :)

-------------------------------------------------
www.McGregorFineArt.com

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Am 13.12.2011 00:40, schrieb Robert McGregor:

>Beautifully done sir, as always

As you were!

But I really do not have any rank in Starfleet ;)

-Ive

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"Ive" <ive### [at] lilysoftorg> wrote in message news:4ee68d12$1@news.povray.org...
> Am 12.12.2011 22:37, schrieb Dre:
>> Awesome!
>
> Thanks.
>
>>How did you get that real nice blue light to work??
>
> Well, the construction of the ceiling, the dome and the whole lighting is 
> so simple that I'm almost ashamed of it ;)
>
> It is really just a clipped_by sphere and a torus (both with a radial 
> texture and emission) and one spotlight.
> The spotlight simulates two things at once:
> - the "daylight lamp" that would simulate the sun within the arboretum and 
> is currently close to zenith.
> - the "light tubes" surrounding the dome.
> The radius of the spotlight matches exactly the dome radius and the 
> falloff is adjusted to match the top of the port and starboard window 
> walls. It is yellow/red to compensate for the blue dome color and the blue 
> tint produced by radiosity. So we get an average white daylight condition 
> under the dome and a slightly bluish tint at the outside due the falloff 
> of the spotlight.
>
>   light_source { <0,10,0>  rgb <0.90, 0.85, 0.75>*5
>     spotlight point_at <0,0,0> radius 48 falloff 66
>     area_light x*0.67 z*0.67 5,5 adaptive 2 circular orient
>     fade_power 2 fade_distance FD*2
>     projected_through {Ceiling}
>   }
>
> This together with moderate radiosity settings
>
>   radiosity {
>     pretrace_start 0.08
>     pretrace_end   2/max(image_width,image_height)
>     count 250
>     nearest_count 10
>     error_bound 0.45
>     recursion_limit 1
>     low_error_factor 0.5
>     gray_threshold 0
>     minimum_reuse 0.015
>     brightness 1.0
>     adc_bailout 0.01/2
>     always_sample off
>     normal off
>   }
>
> produced the original image at 1920x1080 pixel within 24 hours - and I 
> consider this also as quite moderate given the incredible amount of grass 
> blades, leaves and petals ;)
>
> -Ive

Great stuff, sometimes the simple things are the best way to do things!

Thanks for the description, I'll sure have a play with that and see what I 
can come up with :)

Cheers Dre

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On 13-12-2011 1:31, Ive wrote:
> But I really do not have any rank in Starfleet ;)

Arboretum First Officer, I would say  ;-)

Thomas

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> light_source { <0,10,0> rgb <0.90, 0.85, 0.75>*5
> spotlight point_at <0,0,0> radius 48 falloff 66
> area_light x*0.67 z*0.67 5,5 adaptive 2 circular orient
> fade_power 2 fade_distance FD*2
> projected_through {Ceiling}
> }
>
> -Ive

Here, adaptive have no effect.
adaptive 1 start at 3 by 3
adaptive 2 start at 5 by 5
adaptive 3 start at 9 by 9
...

area_light x*0.67 z*0.67 9,9 adaptive 2 circular orient only have a 
marginal advantage.
adaptive 2 start to have a notable speed advantage at 17 by 17 and more.



Alain

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Ive <ive### [at] lilysoftorg> wrote:
> Inside the arboretum...

Wow, Ive, that's an awesome render. I especially like the ground cover; it
really gives me some ideas :)

~Sam

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Am 18.12.2011 01:40, schrieb Samuel Benge:
>
> I especially like the ground cover; it
> really gives me some ideas :)
>

Great. To me your images have always been a source of inspiration ;) and 
I really like your ongoing experimenting and your incredible good eye 
for details.

-Ive

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Am 15.12.2011 05:41, schrieb Alain:
> Here, adaptive have no effect.
> adaptive 1 start at 3 by 3
> adaptive 2 start at 5 by 5
> adaptive 3 start at 9 by 9
> ...
>
> area_light x*0.67 z*0.67 9,9 adaptive 2 circular orient only have a
> marginal advantage.
> adaptive 2 start to have a notable speed advantage at 17 by 17 and more.
>

Hmm, I'm not sure if I understand you correct. You mean using adaptive 2 
makes only sense when using *more* than 5 by 5, right?

Actually I never did a serious speed/quality trade-off compare regarding 
area_lights parameters and used more a "I guess this might work" and 
alternatively a "better more than less" approach. Probably not a good 
idea, so thanks for the head up.

-Ive

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Ive <ive### [at] lilysoftorg> wrote:
> Hmm, I'm not sure if I understand you correct. You mean using adaptive 2
> makes only sense when using *more* than 5 by 5, right?

Yes.  These are from my notes:

  Array Size   Maximum Useful Value   Break-Even Value
    2 x 2              none                  0
    3 x 3               0                    1
    5 x 5               1                    2
    9 x 9               2                    3
   17 x 17              3                    4
   33 x 33              4                    5

Accordingly, adaptive 2 has no effect on 5 by 5.

> Actually I never did a serious speed/quality trade-off compare regarding
> area_lights parameters and used more a "I guess this might work" and
> alternatively a "better more than less" approach. Probably not a good
> idea, so thanks for the head up.

I've done such comparisons, based on Alain's advice.  My general findings are:

  - Adaptive 0 tends to produce unrealistic effects, especially if
    an object (e.g., the lamp fixture!) is close to the light source.

  - Adaptive 1 is sufficient; I haven't had the need to go higher.

  - IIRC, 9 by 9 adaptive 0 was faster than 5 by 5 adaptive 1.  (I
    don't know if that test can be generalized.)  However, the poor
    quality of the adaptive 0 usually isn't worth the speed advantage.

  - Jitter helps.

  - 9 by 9 adaptive 1 is usually a good setting.

However, I haven't tested 9 by 9 adaptive 1 against 5 by 5 adaptive 2.

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