POV-Ray : Newsgroups : povray.general : Lighting problem at extreme distances Server Time
31 Jul 2024 02:22:45 EDT (-0400)
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From: Nicolas Alvarez
Subject: Re: Lighting problem at extreme distances
Date: 25 Mar 2008 11:09:49
Message: <47e923cd$1@news.povray.org>
Warp escribió:
> Nicolas Alvarez <nic### [at] gmailisthebestcom> wrote:
>> Hmm... Looks like there are some C++ wrappers around MPFR that would 
>> make it quite simpler. And when I say simpler, I mean that in many 
>> cases, replacing 'double' with 'mpfr_class' would be all (who said 
>> operator overloading was bad?)
> 
>   There may be wrappers, but are they efficient?

Using MPFR wouldn't be efficient in the first place (compared to plain 
old doubles), so...


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From: Warp
Subject: Re: Lighting problem at extreme distances
Date: 25 Mar 2008 12:31:31
Message: <47e936f2@news.povray.org>
Nicolas Alvarez <nic### [at] gmailisthebestcom> wrote:

> > Nicolas Alvarez <nic### [at] gmailisthebestcom> wrote:
> >> Hmm... Looks like there are some C++ wrappers around MPFR that would 
> >> make it quite simpler. And when I say simpler, I mean that in many 
> >> cases, replacing 'double' with 'mpfr_class' would be all (who said 
> >> operator overloading was bad?)
> > 
> >   There may be wrappers, but are they efficient?

> Using MPFR wouldn't be efficient in the first place (compared to plain 
> old doubles), so...

  That's not really what I asked.

-- 
                                                          - Warp


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From: Sherry Shaw
Subject: Re: Lighting problem at extreme distances
Date: 26 Mar 2008 07:51:22
Message: <47ea46ca@news.povray.org>
Mike Williams wrote:
> If you're going to be combining nearby objects (such as a spaceship) and 
> astronomical objects (such as Sedna) in the same scene, you may need to 
> break the scaling.
> 

I wonder if it might be possible to break the scaling in such a way as 
to have one's cake and eat it too...?  What just occurred to me was the 
sample "Desk" scene, which is rendered as a three-frame animation in 
order to create a recursive image in the photo on the desk.  For example:

Write the scene as a two-frame animation.  When frame_number = 0, render 
only the very distant objects, with one POV unit = a very big number. 
When frame_number = 1, render the closer objects with one POV unit = a 
smaller number; use the output from the first frame as an image_map 
applied to a plane or box in the background of the second frame.

By putting actual, legitimate scaling factors into your code, you can 
therefore argue that you haven't "broken" the scale at all, but merely 
dragged it, kicking and screaming, into the real world.

I think this would work, but I've just barely finished my first cup of 
coffee...  ;)

--Sherry Shaw


-- 
#macro T(E,N)sphere{x,.4rotate z*E*60translate y*N pigment{wrinkles scale
.3}finish{ambient 1}}#end#local I=0;#while(I<5)T(I,1)T(1-I,-1)#local I=I+
1;#end camera{location-5*z}plane{z,37 pigment{granite color_map{[.7rgb 0]
[1rgb 1]}}finish{ambient 2}}//                                   TenMoons


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From: Doctor John
Subject: Re: Lighting problem at extreme distances
Date: 26 Mar 2008 15:09:01
Message: <47eaad5d$1@news.povray.org>
Sherry Shaw wrote:
> Mike Williams wrote:
>> If you're going to be combining nearby objects (such as a spaceship)
>> and astronomical objects (such as Sedna) in the same scene, you may
>> need to break the scaling.
>>
> 
> I wonder if it might be possible to break the scaling in such a way as
> to have one's cake and eat it too...?  What just occurred to me was the
> sample "Desk" scene, which is rendered as a three-frame animation in
> order to create a recursive image in the photo on the desk.  For example:
> 
> Write the scene as a two-frame animation.  When frame_number = 0, render
> only the very distant objects, with one POV unit = a very big number.
> When frame_number = 1, render the closer objects with one POV unit = a
> smaller number; use the output from the first frame as an image_map
> applied to a plane or box in the background of the second frame.
> 
> By putting actual, legitimate scaling factors into your code, you can
> therefore argue that you haven't "broken" the scale at all, but merely
> dragged it, kicking and screaming, into the real world.
> 
> I think this would work, but I've just barely finished my first cup of
> coffee...  ;)
> 
> --Sherry Shaw
> 
> 
I agree, Sherry. IIRC I posted an image here a few years ago using the
same technique. Mine was a monitor showing a monitor showing a monitor
etc etc.
BTW How was the coffee?

John

-- 
I will be brief but not nearly so brief as Salvador Dali, who gave the
world's shortest speech. He said, "I will be so brief I am already
finished," then he sat down.


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From: Nicolas Alvarez
Subject: Re: Lighting problem at extreme distances
Date: 26 Mar 2008 15:10:38
Message: <47eaadbe$1@news.povray.org>

> I agree, Sherry. IIRC I posted an image here a few years ago using the
> same technique. Mine was a monitor showing a monitor showing a monitor
> etc etc.

http://www.infinitecat.com/


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From: Thomas de Groot
Subject: Re: Lighting problem at extreme distances
Date: 27 Mar 2008 02:48:23
Message: <47eb5147$1@news.povray.org>
"Nicolas Alvarez" <nic### [at] gmailisthebestcom> schreef in bericht 
news:47eaadbe$1@news.povray.org...
>
> http://www.infinitecat.com/

LOL

Thomas
[from a cat lover]


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From: Sherry Shaw
Subject: Re: Lighting problem at extreme distances
Date: 27 Mar 2008 21:24:52
Message: <47EC56CC.9080508@aol.com>
Doctor John wrote:
> BTW How was the coffee?

(Heavy sigh)  Instant.

--Sherry Shaw


-- 
#macro T(E,N)sphere{x,.4rotate z*E*60translate y*N pigment{wrinkles scale
.3}finish{ambient 1}}#end#local I=0;#while(I<5)T(I,1)T(1-I,-1)#local I=I+
1;#end camera{location-5*z}plane{z,37 pigment{granite color_map{[.7rgb 0]
[1rgb 1]}}finish{ambient 2}}//                                   TenMoons


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From: Sherry Shaw
Subject: Re: Lighting problem at extreme distances
Date: 27 Mar 2008 21:27:34
Message: <47ec5796@news.povray.org>
Nicolas Alvarez wrote:
> http://www.infinitecat.com/

OMG, LOL!

Possum, Patches, and Lord Greyfluffy express their appreciation.

--Sherry Shaw


-- 
#macro T(E,N)sphere{x,.4rotate z*E*60translate y*N pigment{wrinkles scale
.3}finish{ambient 1}}#end#local I=0;#while(I<5)T(I,1)T(1-I,-1)#local I=I+
1;#end camera{location-5*z}plane{z,37 pigment{granite color_map{[.7rgb 0]
[1rgb 1]}}finish{ambient 2}}//                                   TenMoons


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