A scene with 1000 randomly placed light sources with distance-dependent 
attenuation (fade_power, fade_distance).

First image: POV-Ray 3.7, render time 73s.

Second image: experimental patch, render time 9s.

For each light source, the patch automatically computes a cutoff 
distance based on light source brightness, fade parameters, and a global 
threshold (currently this is the global adc_bailout setting). Beyond 
this distance, the lights source is simply ignored.

(As an alternative, the patch also allows for manually specifying the 
cutoff distance, but that's not used in this scene.)

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Attachments:
Download 'fade_light_pov37.png' (293 KB) Download 'fade_light_upov.png' (281 KB)

Preview of image 'fade_light_pov37.png'

Preview of image 'fade_light_upov.png'

On 29/01/14 02:19, clipka wrote:
> A scene with 1000 randomly placed light sources with distance-dependent
> attenuation (fade_power, fade_distance).
> 
> First image: POV-Ray 3.7, render time 73s.
> 
> Second image: experimental patch, render time 9s.
> 
> For each light source, the patch automatically computes a cutoff
> distance based on light source brightness, fade parameters, and a global
> threshold (currently this is the global adc_bailout setting). Beyond
> this distance, the lights source is simply ignored.
> 
> (As an alternative, the patch also allows for manually specifying the
> cutoff distance, but that's not used in this scene.)

That was fast! I can only stand in awe of your achievements.

John
-- 
Protect the Earth
It was not given to you by your parents
You hold it in trust for your children

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I think this is exactly what the original supplicant was asking for. 
That is a nice addition to our favourite program.

Thomas

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>clipka  on date 29/01/2014 3.19 wrote:
> For each light source, the patch automatically computes a cutoff
> distance based on light source brightness, fade parameters, and a global
> threshold (currently this is the global adc_bailout setting). Beyond
> this distance, the lights source is simply ignored.
A notable result.
Please, promote the patch to release!
;-)
Paolo

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clipka <ano### [at] anonymousorg> wrote:
> A scene with 1000 randomly placed light sources with distance-dependent
> attenuation (fade_power, fade_distance).
>
> First image: POV-Ray 3.7, render time 73s.
>
> Second image: experimental patch, render time 9s.
>
> For each light source, the patch automatically computes a cutoff
> distance based on light source brightness, fade parameters, and a global
> threshold (currently this is the global adc_bailout setting). Beyond
> this distance, the lights source is simply ignored.
>
> (As an alternative, the patch also allows for manually specifying the
> cutoff distance, but that's not used in this scene.)

Hey, that looks pretty nice there; it reminds me of the MegaPov Glows a bit. ;)

Ian

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Am 29.01.2014 19:22, schrieb [GDS|Entropy]:
> clipka <ano### [at] anonymousorg> wrote:
>> A scene with 1000 randomly placed light sources with distance-dependent
>> attenuation (fade_power, fade_distance).
>>
>> First image: POV-Ray 3.7, render time 73s.
>>
>> Second image: experimental patch, render time 9s.
>>
>> For each light source, the patch automatically computes a cutoff
>> distance based on light source brightness, fade parameters, and a global
>> threshold (currently this is the global adc_bailout setting). Beyond
>> this distance, the lights source is simply ignored.
>>
>> (As an alternative, the patch also allows for manually specifying the
>> cutoff distance, but that's not used in this scene.)
>
> Hey, that looks pretty nice there; it reminds me of the MegaPov Glows a bit. ;)
>
> Ian

No, just a bunch of ordinary lights with matching looks_like emissive 
spheres, placed neatly on the floor. Place them somewhere in mid-air and 
most of the visual magic is gone.

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Very nice, thank you! It sounds strangely familiar ;)

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clipka <ano### [at] anonymousorg> wrote:
> A scene with 1000 randomly placed light sources with distance-dependent
> attenuation (fade_power, fade_distance).
>
> First image: POV-Ray 3.7, render time 73s.
>
> Second image: experimental patch, render time 9s.
>
> For each light source, the patch automatically computes a cutoff
> distance based on light source brightness, fade parameters, and a global
> threshold (currently this is the global adc_bailout setting). Beyond
> this distance, the lights source is simply ignored.
>
> (As an alternative, the patch also allows for manually specifying the
> cutoff distance, but that's not used in this scene.)

Cool work, Christoph!

There's something odd going on between the two images you posted: the spheres in
the UberPOV version are noticeably darker, but the plane is not. Did you change
the spheres' material settings between renders?

Sam

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Am 30.01.2014 20:24, schrieb Samuel Benge:

> There's something odd going on between the two images you posted: the spheres in
> the UberPOV version are noticeably darker, but the plane is not. Did you change
> the spheres' material settings between renders?

You mean the diffuse spheres, right?

No, that's not odd at all:

- The darkening of the spheres of course comes from the fact that even 
though the cut-off light sources don't contribute much brightness 
individually, they still do contribute a good deal in total.

- The (apparent) non-darkening of the plane comes from the fact that 
here the contribution of the individual light sources isn't just 
affected by the inverse-square distance-based falloff, but also the 
falloff due to the angle of incidence.

If you'd use a "brilliance 0" finish on the plane (causing diffuse 
brightness to be entirely independent of the angle of incidence), the 
darkening effect would be just as visible on the plane as it is on the 
spheres.

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clipka <ano### [at] anonymousorg> wrote:
> A scene with 1000 randomly placed light sources with distance-dependent
> attenuation (fade_power, fade_distance).
>
> First image: POV-Ray 3.7, render time 73s.
>
> Second image: experimental patch, render time 9s.
>
> For each light source, the patch automatically computes a cutoff
> distance based on light source brightness, fade parameters, and a global
> threshold (currently this is the global adc_bailout setting). Beyond
> this distance, the lights source is simply ignored.
>
> (As an alternative, the patch also allows for manually specifying the
> cutoff distance, but that's not used in this scene.)

How does the patch deal with radiosity? does it still provide an improvement?
any order of magnitude for it?

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