POV-Ray : Newsgroups : povray.general : Photons Vs RAM Server Time
4 Aug 2024 16:08:09 EDT (-0400)
  Photons Vs RAM (Message 1 to 7 of 7)  
From: Rafal 'Raf256' Maj
Subject: Photons Vs RAM
Date: 26 Feb 2003 23:17:02
Message: <Xns932F361B3E304raf256com@204.213.191.226>
Hi, I have another problem with photon, after I get them to work correctly, 
I 'fight' with ocean scene. This scene is using way to much memory :-/
Scene looks like :


  * light source (parrelal rays)


.--- ocean 'wals' - difference of 2 cyliders
V
|------| water surface intersection{plane y=5 and cylinder }
|      |
|      |
|      |
..'.'... ocean follr - height field

I'm going to add another cylinder that would be a media container.

This are importants facts about scene, maybe some of them can be done 
better ?
- ground fog is used to nicely hide distance details, and is used togather 
with media(scatering/absorbion) because fog calculates much faster
- water surface is thin - it's a plane (intersected with ocean shape, to 
avoid shooting photons on infinite object). I used ior=1.5 instead of 1.3 
to get nicer artistic effects
- all area below water surface and ocean floor has ior=1.0 
- I didn't used distpersion as it would generate too much photons to fit in 
memory

- when I set too small spacing, POV allocated over 2 GB RAM, and then XP 
died with blue screen of death :-/ it happened several times. Can POV 
alocate over 2 GB ? Maybe I should instal a real OS like Linux?
- I have 512 DDR RAM, and 60 GB IBM (with overheated during 2 GB render to 
50 C)



-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M


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From: Slime
Subject: Re: Photons Vs RAM
Date: 26 Feb 2003 23:20:11
Message: <3e5d91fb@news.povray.org>
Take my advice: Don't bother with media photons. Use faked causics instead.
The difference, with media, is almost unnoticeable.

When it comes to surface photons, make sure you're only shooting them at the
parts of the scene that are actually visible.

 - Slime
[ http://www.slimeland.com/ ]


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From: Rafal 'Raf256' Maj
Subject: Re: Photons Vs RAM
Date: 26 Feb 2003 23:29:02
Message: <Xns932F382418A3Araf256com@204.213.191.226>
"Slime" <slm### [at] slimelandcom> wrote in news:3e5d91fb@news.povray.org

> Take my advice: Don't bother with media photons. Use faked causics
> instead. The difference, with media, is almost unnoticeable.

Hmm, I thing I will concider this :)
 
> When it comes to surface photons, make sure you're only shooting them
> at the parts of the scene that are actually visible.

It's exacly what I thought same, but how can this be achived ?

Imho it would be a greate idea to add possibility to set separate spacing 
for areas that are directly viewed by camera ?

-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M


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From: Rafal 'Raf256' Maj
Subject: Re: Photons Vs RAM
Date: 27 Feb 2003 00:05:03
Message: <Xns932F3E3EAEACCraf256com@204.213.191.226>
"Rafal 'Raf256' Maj" <raf### [at] raf256com> wrote in
news:Xns### [at] 204213191226 

[...]

I tried to used caustics, but - caustics looked good only with 
  caustics 10000
with imho is a quite strange value. My water surface object is:

cylinder { y*4.9, y*4.95, scSeeRad*1.01
  pigment { rgbf <.50,.90,.98, .92> }
  normal { bozo .1 scale .4 }
  finish { reflection { .1 .3 } conserve_energy  }   
  interior {
    ior 1.30
    caustics 20000
  }                                     
  // photons { refraction 1  reflection 0  target 1 }
}  


-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M


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From: Rafal 'Raf256' Maj
Subject: Re: Photons Vs RAM
Date: 27 Feb 2003 13:27:20
Message: <Xns932FC6465A3E5raf256com@204.213.191.226>
"Rafal 'Raf256' Maj" <raf### [at] raf256com> wrote in 
news:Xns### [at] 204213191226

[...]

And here are some results of my work...

http://raf256.com/show/ocean/



-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M


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From: Slime
Subject: Re: Photons Vs RAM
Date: 28 Feb 2003 19:11:30
Message: <3e5ffab2$1@news.povray.org>
All of those images, at least down to 3.png, are extremely excellent and
very pretty.

 - Slime
[ http://www.slimeland.com/ ]


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From: Greg Edwards
Subject: Re: Photons Vs RAM
Date: 6 Mar 2003 20:06:51
Message: <fgs04f4k1rsr$.1uqx3uvzvez3o.dlg@40tude.net>
On 26 Feb 2003 23:17:02 -0500, Rafal 'Raf256' Maj wrote:

> Hi, I have another problem with photon, after I get them to work correctly, 
> I 'fight' with ocean scene. This scene is using way to much memory :-/
> Scene looks like :
> 
> 
>   * light source (parrelal rays)
> 
> 
> .--- ocean 'wals' - difference of 2 cyliders
> V
> |------| water surface intersection{plane y=5 and cylinder }
> |      |
> |      |
> |      |
> ..'.'... ocean follr - height field
> 
> I'm going to add another cylinder that would be a media container.
> 
> This are importants facts about scene, maybe some of them can be done 
> better ?
> - ground fog is used to nicely hide distance details, and is used togather 
> with media(scatering/absorbion) because fog calculates much faster
> - water surface is thin - it's a plane (intersected with ocean shape, to 
> avoid shooting photons on infinite object). I used ior=1.5 instead of 1.3 
> to get nicer artistic effects
> - all area below water surface and ocean floor has ior=1.0 
> - I didn't used distpersion as it would generate too much photons to fit in 
> memory
> 
> - when I set too small spacing, POV allocated over 2 GB RAM, and then XP 
> died with blue screen of death :-/ it happened several times. Can POV 
> alocate over 2 GB ? Maybe I should instal a real OS like Linux?
> - I have 512 DDR RAM, and 60 GB IBM (with overheated during 2 GB render to 
> 50 C)

At any point did you set POV's priority to anything higher than AboveNormal 
in the task manager? I think that ifyou set POV's priority high enough, it 
will steal time from the memory manager and it won't be able to get enough 
memory for its trace and BOOM!!
Setting POV's priority to no higher than AboveNormal has cured the problem 
for me and I hope it helps you too!

-- 
camera{location 2*y-.9rotate -z*9direction z/1.5look_at y}global_settings{
max_trace_level 99ambient_light 10}#macro G(V,E)pigment{V}finish{diffuse 0
ambient .1-E/10reflection{E metallic}}#end#macro O(N,T)plane{y,N G(T,0)
hollow}#end#macro C(A)sphere{0,A#end O(9,blue 1)O(-1,rgb 1)box{1+9*y,-y-1G(
rgb 1,.95)hollow}C(.99)G(rgb 1,1)}C(1)G(red 1,1)no_reflection}// Greg E


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