I'm working on a scene which I would eventually like to light with numerous
"torches" (point lights with fade_distance & fade_power).  Is there a way,
in order to speed up rendering, to cause illumination to be calculated only
for objects within a certain distance of the light source, ignoring those
further away for which the amount of illumination contributed would be very
small?

Thanks in advance for replies.

Regards,
Mike C.

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Mike the Elder <zer### [at] wyanorg> wrote:
> I'm working on a scene which I would eventually like to light with numerous
> "torches" (point lights with fade_distance & fade_power).  Is there a way,
> in order to speed up rendering, to cause illumination to be calculated only
> for objects within a certain distance of the light source, ignoring those
> further away for which the amount of illumination contributed would be very
> small?

  You could try to divide your scene into sections and then use
light groups to selectively light only certain sections with certain
lights.

-- 
                                                          - Warp

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Warp <war### [at] tagpovrayorg> wrote:
>
>   You could try to divide your scene into sections and then use
> light groups to selectively light only certain sections with certain
> lights.
>
> --
>                                                           - Warp

I'm hoping that I won't have to do that because the scene contains long
"walls" that would have to be broken up into pieces that could be included
or excluded from the various light groups, but still, that's the best
option so far and I thank you for it.

Regards,
Mike C.

Post a reply to this message

"Mike the Elder" <zer### [at] wyanorg> wrote:
> Warp <war### [at] tagpovrayorg> wrote:
> >
> >   You could try to divide your scene into sections and then use
> > light groups to selectively light only certain sections with certain
> > lights.
> >
> > --
> >                                                           - Warp
>
> I'm hoping that I won't have to do that because the scene contains long
> "walls" that would have to be broken up into pieces that could be included
> or excluded from the various light groups, but still, that's the best
> option so far and I thank you for it.
>
> Regards,
> Mike C.

You could also define a distance vector from the camera to the light source,
then check that before the rendering and only render those that are within
some threshold.

Good luck,
Mike S.

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Mike Sobers <sob### [at] mindspringcom> wrote:
> You could also define a distance vector from the camera to the light source,
> then check that before the rendering and only render those that are within
> some threshold.

  I don't think turning off lights was what he was asking.

-- 
                                                          - Warp

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That the exact use of fade_power parameters.. you just need to increase it
up to 1, and additionaly modify your fade distance factor






news:web.464df9a83f9f67649073c0250@news.povray.org...
> I'm working on a scene which I would eventually like to light with
numerous
> "torches" (point lights with fade_distance & fade_power).  Is there a way,
> in order to speed up rendering, to cause illumination to be calculated
only
> for objects within a certain distance of the light source, ignoring those
> further away for which the amount of illumination contributed would be
very
> small?
>
> Thanks in advance for replies.
>
> Regards,
> Mike C.
>
>
>
>

Post a reply to this message

note that, if your fade power is already high (up to 3) , that means that
your parameters are not well made..you must then reset your fade_power to 1,
or 0.9 (what i done often) , and then found the appropriate fade_distance
value ..
after you can play with the fade_power parameters to define the appropriate
level of attenuation .





news:466d5d43@news.povray.org...
> That the exact use of fade_power parameters.. you just need to increase it
> up to 1, and additionaly modify your fade distance factor
>
>
>
>
>

> news:web.464df9a83f9f67649073c0250@news.povray.org...
> > I'm working on a scene which I would eventually like to light with
> numerous
> > "torches" (point lights with fade_distance & fade_power).  Is there a
way,
> > in order to speed up rendering, to cause illumination to be calculated
> only
> > for objects within a certain distance of the light source, ignoring
those
> > further away for which the amount of illumination contributed would be
> very
> > small?
> >
> > Thanks in advance for replies.
> >
> > Regards,
> > Mike C.
> >
> >
> >
> >
>
>

Post a reply to this message

"Penelope20k" <pen### [at] caramailfr> wrote:
> note that, if your fade power is already high (up to 3) , that means that
> your parameters are not well made..you must then reset your fade_power to 1,
> or 0.9 (what i done often) , and then found the appropriate fade_distance
> value ..
> after you can play with the fade_power parameters to define the appropriate
> level of attenuation .


> news:466d5d43@news.povray.org...
> > That the exact use of fade_power parameters.. you just need to increase it
> > up to 1, and additionaly modify your fade distance factor
> >

Thanks for the help.
-Mike C.

Post a reply to this message

Mike the Elder <web.464df9a83f9f67649073c0250@news.povray.org> Friday, 18
May 2007 21:08

> those further away for which the amount of illumination contributed would
> be very small?
> Thanks in advance for replies.

I had simmilar idea back like... 3, 4 years ago :) Actually was one of my
first questions to news ever afair.

Light groups are not very comfortable to use, and stronger fade alone doesnt
give performence improvement.

Idea to ignore very distant lights would be nice IMHO.

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