How many objects I can place in a scene? Thousands, millions, billions?
To be more specific lets say I want to draw a scene with 1 million spheres.
How much time it will take (roughly, on a modern PC) ? What are the critical
characteristics of a computer (cache, frequency, CPU, memory, graphic card)
which would let me plot more objects faster?

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Transient <nomail@nomail> wrote:
> How many objects I can place in a scene?

  How much memory do you have?

> To be more specific lets say I want to draw a scene with 1 million spheres.
> How much time it will take (roughly, on a modern PC) ?

  Depends on your rendering settings, lighting, texturing, resolution, etc.
Anything from a few seconds to hours.

> What are the critical
> characteristics of a computer (cache, frequency, CPU, memory, graphic card)
> which would let me plot more objects faster?

  CPU. Memory speed has some effect too.

-- 
                                                          - Warp

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Warp <war### [at] tagpovrayorg> wrote:
> Transient <nomail@nomail> wrote:
> > How many objects I can place in a scene?
>
>   How much memory do you have?

      2 Gb. Can extend to 4 Gb - should I do that?

>
> > To be more specific lets say I want to draw a scene with 1 million spheres.
> > How much time it will take (roughly, on a modern PC) ?
>
>   Depends on your rendering settings, lighting, texturing, resolution, etc.
> Anything from a few seconds to hours.

     I need the quality that is called "stunning" - is it still within
"hours"?
>
> > What are the critical
> > characteristics of a computer (cache, frequency, CPU, memory, graphic card)
> > which would let me plot more objects faster?
>
>   CPU. Memory speed has some effect too.

   Thanks a lot for the answer
>
> --
>                                                           - Warp

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#declare SD=seed(255);

blob {
 threshold .05
 #declare index=0;
 #while(index<50000)
  sphere {5*(0.5-<rand(SD),rand(SD),rand(SD)>),rand(SD),5 }
  #declare index=index+1;
 #end
 pigment {rgb 1}
 hollow
 }

This script 50 000 spheres took lest than 5minutes to render on a 933Mhz
512k windows 98 PC


for 500 000, the scene starts to draw at 2m 03 s.. no problem  of memory ...











news:web.469b4f19c04c333f2345a0210@news.povray.org...
> How many objects I can place in a scene? Thousands, millions, billions?
> To be more specific lets say I want to draw a scene with 1 million
spheres.
> How much time it will take (roughly, on a modern PC) ? What are the
critical
> characteristics of a computer (cache, frequency, CPU, memory, graphic
card)
> which would let me plot more objects faster?
>
>
>

Post a reply to this message

Transient wrote:
> How many objects I can place in a scene? Thousands, millions,
> billions? To be more specific lets say I want to draw a scene with 1
> million spheres. How much time it will take (roughly, on a modern PC)
> ? What are the critical characteristics of a computer (cache,
> frequency, CPU, memory, graphic card) which would let me plot more
> objects faster?

I think you should consider using a 64bit CPU and run 64 bit software on
it. The amount of memory one process can point to is restricted by the
size of pointers. 64 bit CPUs use pointers that are 64 bit log. As far
as I know, the limit on 32 bit CPUs is in practice about 4GB (per
process). On 64 bit CPUs you surely will never reach the maximum.

You can try to estimated the memory usage yourself. Assume 100 bytes per
sphere. This would yield only 100 Mb. So, one million isn't that much
at all. (And you don't even need a 64 bit CPU)

The other things are:
- Number of CPUs (as many as possible)
- Speed of the CPUs
- RAM speed

You should simply try to see what's possible.

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Wasn't it Transient who wrote:
>How many objects I can place in a scene? Thousands, millions, billions?
>To be more specific lets say I want to draw a scene with 1 million spheres.
>How much time it will take (roughly, on a modern PC) ? What are the critical
>characteristics of a computer (cache, frequency, CPU, memory, graphic card)
>which would let me plot more objects faster?

It depends on what sort of shortcuts you're willing to accept.

I have rendered a scene that had 20 billion polygons in it, but that was
achieved by having many copies of the same mesh in the scene. If I
hadn't used that trick, then I once calculated that the source for the
image would have had a file size of 1.7 Terabytes.

I've never really pushed the limits with discrete objects, like spheres,
but POV whizzes through the processing of a million spheres. Try this
scene:

global_settings {assumed_gamma 1.0}
#declare M=100;
union {
  #declare X=0;
  #while (X<M)
    #declare Y=0;
    #while (Y<M)
      #declare Z=0;
      #while (Z<M)
        sphere{<X,Y,Z>,1}
        #declare Z=Z+1;
      #end
      #declare Y=Y+1;
    #end
    #declare X=X+1;
  #end 
  pigment {rgb 1}
}
camera {location  <1.5,1.5,-1>*M look_at <M,M,M>/2}
light_source {<3, 10, -30>*M color rgb 1}

Memory is going to be the limiting feature when dealing with sheer
numbers of objects. POV says that the "peak memory used" for those
million spheres was 290 Mb, but the scene with the 20 billion polygons
used far less - I ran it on a machine that only had 256Mb of memory, and
Windows ate a considerable percentage of that.

Note that the graphics card has no effect on the speed of POVRay. The
computer that I used for the 20 billion polygons image didn't have a
graphics card.

-- 
Mike Williams
Gentleman of Leisure

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Oh yes, here's the image with 20 billion polygons in it. It's a picture
of the day that Smithers violated the corporation's dress code. 

http://www.econym.demon.co.uk/temp/thecorporation.jpg

-- 
Mike Williams
Gentleman of Leisure

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Transient <nomail@nomail> wrote:
> Warp <war### [at] tagpovrayorg> wrote:
> > Transient <nomail@nomail> wrote:
> > > How many objects I can place in a scene?
> >
> >   How much memory do you have?

>       2 Gb. Can extend to 4 Gb - should I do that?

  It was a rhetorical question.

> >   Depends on your rendering settings, lighting, texturing, resolution, etc.
> > Anything from a few seconds to hours.

>      I need the quality that is called "stunning" - is it still within
> "hours"?

  It depends on your rendering settings, lighting, texturing, resolution, etc.

  An image which takes 1 minute to render can look absolutely stunning, and
an image which takes 10 hours to render can look like crap. There's no rule
of thumb. It just depends on your creative skills and usage of the program.

-- 
                                                          - Warp

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Mike Williams nous apporta ses lumieres en ce 2007/07/16 11:09:
> Oh yes, here's the image with 20 billion polygons in it. It's a picture
> of the day that Smithers violated the corporation's dress code. 
> 
> http://www.econym.demon.co.uk/temp/thecorporation.jpg
> 
So, Smithers is the guy with the RED tie, or am I mistaken?

-- 
Alain
-------------------------------------------------
Educate and inform the whole mass of the people... They are the only sure
reliance for the preservation of our liberty.
Thomas Jefferson

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Transient nous apporta ses lumieres en ce 2007/07/16 06:57:
> How many objects I can place in a scene? Thousands, millions, billions?
> To be more specific lets say I want to draw a scene with 1 million spheres.
> How much time it will take (roughly, on a modern PC) ? What are the critical
> characteristics of a computer (cache, frequency, CPU, memory, graphic card)
> which would let me plot more objects faster?
> 
> 
> 
Top factor: CPU FAST, effecient, multiple and/or multicores.
Next: RAM as much as you can install, high quality with minimum latency.
More cache can help, but you don't have control on that.
Fast hard drive with an optimised swap file if you need to use the swap file 
when rendering, more RAM will reduce that need.

Pointless item: the video card as the GPU is hardly ever used when refreshing 
the preview display. You could have an old ISA B/W 8Kb card and still have the 
same rendering performances.

-- 
Alain
-------------------------------------------------
The tree of liberty must be refreshed from time to time with the blood of
patriots and tyrants.
Thomas Jefferson

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