The attached is a scene I created at scale 1 POV unit is a metre.  I then
scaled the objects and camera by .001 (sc=.001) to make 1 POV unit is 1
kilometer.  You will notice that the shadows cast by the objects are
incomplete.  Set sc to 1 or .01 and the shadows are correct.

John Ridgway

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Attachments:
Download 'world_1.pov.txt' (2 KB)

"John Ridgway" <joh### [at] ridgwaydesignfsnetcouk> wrote in 
news:3c53b38e@news.povray.org:

> The attached is a scene I created at scale 1 POV unit is a metre.  I then
> scaled the objects and camera by .001 (sc=.001) to make 1 POV unit is 1
> kilometer.  You will notice that the shadows cast by the objects are
> incomplete.  Set sc to 1 or .01 and the shadows are correct.

Confirmed.

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Wasn't it John Ridgway who wrote:
>The attached is a scene I created at scale 1 POV unit is a metre.  I then
>scaled the objects and camera by .001 (sc=.001) to make 1 POV unit is 1
>kilometer.  You will notice that the shadows cast by the objects are
>incomplete.  Set sc to 1 or .01 and the shadows are correct.

Confirmed.


Here's the same effect with a simplified scene and in close-up. The
second box doesn't cast a shadow, and there's no shadow cast on it from
the first box.

Enclose the boxes in a merge{}, and the shadows are correct. 


#declare sc=0.001;

//merge {
box{<-.5,0.8,-.5>,<.5,1.2,.5> pigment{rgb 1} scale sc}
box{<-.5,0,-.5>,<.5,.4,.5> pigment{rgb 1} scale sc}
box{<-.5,0,-20>,<20,-.2,20> pigment{rgb 1} scale sc}
//}

background{rgb<1,0,0>} 

light_source{<-200,150,100> rgb 1 } 

camera{
  location<2.5,3.5,-19.5>*sc
  look_at<-100,-150,1000>*sc
  angle 10
}  

-- 
Mike Williams
Gentleman of Leisure

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If you want to see a sphere shrink out of site have a render of the
following, trying those numbers:

// beyond 0.00004, or so, the sphere begins shrinking
// 0.00001001 and the sphere is almost gone @320x240 res.
#declare sc=0.0099;

//union {
box{<-.5,0.8,-.5>,<.5,1.2,.5> pigment{rgb 1} scale sc}
box{<-.5,0,-.5>,<.5,.4,.5> pigment{rgb 1} scale sc}
box{<-.5,0,-20>,<20,-.2,20> pigment{rgb 1} scale sc}
sphere{<2.4,2,2>,1 pigment{rgb 1} scale sc}
//}

background{rgb<1,0,0>}

light_source{<-200,150,100>*sc rgb 1 }

camera{
  location<2,3,-4>*sc
  look_at<-200,-400,1000>*sc
}


I wanted to see if objects still had troubles with very small scales like
they used to and things are much better now.  The sphere primitive used to
disappear at a scale of only 0.002 unit, I believe was the number.  Boxes
were likewise fragile yet lasted into much smaller scales, cones simply held
out forever it seemed.  It's good to see the scaling is much more sturdy
now.  Didn't know shadows were being lost or cast wrong at such relatively
normal scales.  That's something altogether different from actual object
surfaces being seen.

bob h

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