what is a useful size to work with? what are the pro/cons in working with
1px=1 metre or 100px=1 metre?
what do you use and why?
thnx

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I generally use 1 unit = 1 meter, for no better reason than that I tend 
to do starships, which are generally rather large objects.  If I had to 
measure them in centimeters, I'd go mad.  If I tried to measure them in 
milimeters, I might exceed the limits of POV's precision.



>what is a useful size to work with? what are the pro/cons in working with
>1px=1 metre or 100px=1 metre?
>what do you use and why?
>thnx
>
>

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In article <3d62becb@news.povray.org>,


> what is a useful size to work with? what are the pro/cons in working with
> 1px=1 metre or 100px=1 metre?
> what do you use and why?

"px"?
The units in POV have no relation to any specific real-world 
measurement. Or to the generated image for that matter (it looks like 
you might think they are related to pixels for some reason). A unit is 
just a unit, you can use inches, millimeters, kilometers, miles, AU's, 
light years...whatever makes the most sense. You do have to be careful 
with the range of dimensions in your scene, computers have limited 
available precision.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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What are the limits?  I dont thing I've ever used anything bigger then 10000
or closer to 0 then .001, but it would be nice to know.

BTW, I tend to use 1POV = 1inch for small items and 1POV = ~1ft. for large
structure typ object.  IF you pland to distribute models or use other
peoples stick with 1POV = 1cm sence that is a pretty universal standard on
the net.

JFMILLER


"Dawn McKnight" <blu### [at] maccom> wrote in message
news:3D6### [at] maccom...
> I generally use 1 unit = 1 meter, for no better reason than that I tend
> to do starships, which are generally rather large objects.  If I had to
> measure them in centimeters, I'd go mad.  If I tried to measure them in
> milimeters, I might exceed the limits of POV's precision.
>

>
> >what is a useful size to work with? what are the pro/cons in working with
> >1px=1 metre or 100px=1 metre?
> >what do you use and why?
> >thnx
> >
> >
>

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sorry, I meant 1 unit
"Christopher James Huff" <chr### [at] maccom> wrote in message
news:chr### [at] netplexaussieorg...
> In article <3d62becb@news.povray.org>,

>
> > what is a useful size to work with? what are the pro/cons in working
with
> > 1px=1 metre or 100px=1 metre?
> > what do you use and why?
>
> "px"?
> The units in POV have no relation to any specific real-world
> measurement. Or to the generated image for that matter (it looks like
> you might think they are related to pixels for some reason). A unit is
> just a unit, you can use inches, millimeters, kilometers, miles, AU's,
> light years...whatever makes the most sense. You do have to be careful
> with the range of dimensions in your scene, computers have limited
> available precision.
>
> --
> Christopher James Huff <cja### [at] earthlinknet>
> http://home.earthlink.net/~cjameshuff/
> POV-Ray TAG: chr### [at] tagpovrayorg
> http://tag.povray.org/

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In article <3d62eb32@news.povray.org>,
 "jfmiller" <jfm### [at] hotmailcom> wrote:

> What are the limits?  I dont thing I've ever used anything bigger then 10000
> or closer to 0 then .001, but it would be nice to know.

The frame.h file defines two constants, Small_Tolerance and 
Max_Distance. Small_Tolerance is 0.001, and is the closest an 
intersection can get to the beginning of the ray before it is thrown 
away, Max_Distance is 1.0e7 (or 10000000) and is the furthest an 
intersection can get from the ray origin. There is also EPSILON which is 
equal to 1.0e-10 (0.00000000001), anything < EPSILON is usually 
considered 0. Some shapes define their own values...actually, I'm not 
sure if the first two are actually used anywhere.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:
> considered 0. Some shapes define their own values...actually, I'm not
> sure if the first two are actually used anywhere.

Unfortunately in blobs.cpp there is still defined DEPTH_TOLERANCE 1.0e-2 
which quickly can lead to problems. So either be careful with small blobs 
or change this constant and recompile.

- Micha
 
-- 
http://objects.povworld.org - the POV-Ray Objects Collection

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