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From: Alan Smith
Subject: Units of measure
Date: 26 Aug 2003 09:57:13
Message: <3f4b6739$1@news.povray.org>
Am I correct that POV-Ray does not support units of measurement
ie (mm, cm, m, km, in, ft etc)?

Wouldn't it be nice if POV allowed something like :-
box { <-2cm, -1cm, 10mm>,  <2cm, 1cm, 1cm> }

This would lead to more readable code, greater ease of 'real world' scene
modelling with mixed sizes of objects and, most importantly, greater scope
for sharing objects from other people who generously donate their source.

At the moment I achieve this by using suitable declares and coding as :-
box { <-2*cm, -1*cm, 10*mm>,  <2*cm, 1*cm, 1*cm> }


Which goes a long way to meeting my needs, but it still does not do anything
for supporting portability of coded objects between scene files.

This would surely be a simple modification to the parser and would still
leave the ability for people to work in a 'unit-less' fashion if they like?

Alan Smith.


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From: Ken
Subject: Re: Units of measure
Date: 26 Aug 2003 10:02:08
Message: <3F4B67EB.8E194FAB@pacbell.net>
Alan Smith wrote:
> 
> Am I correct that POV-Ray does not support units of measurement
> ie (mm, cm, m, km, in, ft etc)?
> 
> Wouldn't it be nice if POV allowed something like :-
> box { <-2cm, -1cm, 10mm>,  <2cm, 1cm, 1cm> }

I'm all for it as long as it is in inches, feet and yards rather than that
stupid metric system.

-- 
Ken Tyler


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From: S McAvoy
Subject: Re: Units of measure
Date: 26 Aug 2003 10:07:26
Message: <fcqmkv0io729vsl657034tkt17cskisr4p@4ax.com>
On Tue, 26 Aug 2003 07:00:11 -0700, Ken <tyl### [at] pacbellnet> wrote:


>I'm all for it as long as it is in inches, feet and yards rather than that
>stupid metric system.

Hold on, doesn't your lot use decimal feet i.e. ten inches to the foot. I
remember someone at work getting into a mess because he used a rule borrowed
from an American Driller.

Regards
        Stephen


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From: Alan Smith
Subject: Re: Units of measure
Date: 26 Aug 2003 10:11:48
Message: <3f4b6aa4@news.povray.org>
I agree it should support both, and don't wish to open a debate about the
relative merits of
different measuring systems.   At the moment I would achieve this by :-

#declare mm = 0.1;
#declare cm = 1;
#declare m = 100;
#declare in = 2.51*cm;
#declare ft = 12 * in;

but it would be so much nicer (and standardized) if it was built in.

Alan Smith

PS - Note the use of the 'z' in standardized (see I'm really not bothered,
both spelllings work
and I would like to use both!)

"Ken" <tyl### [at] pacbellnet> wrote in message
news:3F4B67EB.8E194FAB@pacbell.net...
>
>
> Alan Smith wrote:
> >
> > Am I correct that POV-Ray does not support units of measurement
> > ie (mm, cm, m, km, in, ft etc)?
> >
> > Wouldn't it be nice if POV allowed something like :-
> > box { <-2cm, -1cm, 10mm>,  <2cm, 1cm, 1cm> }
>
> I'm all for it as long as it is in inches, feet and yards rather than that
> stupid metric system.
>
> -- 
> Ken Tyler


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From: Warp
Subject: Re: Units of measure
Date: 26 Aug 2003 13:14:27
Message: <3f4b9573@news.povray.org>
Ken <tyl### [at] pacbellnet> wrote:
> I'm all for it as long as it is in inches, feet and yards rather than that
> stupid metric system.

  I don't understand why the American system would be better and more
logical.

  A foot has 12 inches. A yard has 3 feet. A mile has 1760 yards.
There's no very logical connection between these units and it's very
hard to convert between them.
  For example, how many feet are there in 4 miles? The answer is 21120.
Very easy to calculate in your head?
  How many yards are there in 11 inches? The answer is: 0.305555

  Compare it to this: How many meters are there in 4 kilometers?
This is very trivial to calculate in your head: 4000.
  How many meters are there in 11 cm? Answer: 0.11

  The whole metric system is based on multiples of 10, and many of these
multiples are named. Do you talk about nanoinches, nanofeet, nanoyards
or nanomiles? How do you usually talk about measures markedly larger
or smaller than the units? Can you convert easily from megainches to
nanomiles?

  Can you tell with a straight face "a mile is 63360 inches, 5280 feet
and 1760 yards, and this system is not stupid"?

-- 
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}//  - Warp -


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From: ingo
Subject: Re: Units of measure
Date: 26 Aug 2003 13:41:03
Message: <Xns93E3C83C8D619seed7@povray.org>
in news:3f4b9573@news.povray.org Warp wrote:

>   Can you tell with a straight face "a mile is 63360 inches, 5280 feet
> and 1760 yards, and this system is not stupid"?
> 

t's a matter of perception. Why would you need to do these conversions? If 
you want to give a certain length or distance it depends on the size what 
kind of unit you choose to express this size in. A baseball field is 120 
yards deep, a distance to travel is expressed in miles, small dimensions 
are in mills or inches, the hight of a plane in feet. Where to put the 
moment that you change from one to another unit is a matter of instict or 
lessons learned, but not completely arbitraily. In this regard the system 
is not different to our metric system. Just that the points of change are 
a bit sharper, it's 90 cm and 1.20 meter. But we also have halve a 
kilometer and 900 meters. A moutain we measure in meters, not kilometers.

Ingo
 ... who only orders his beer in a non metric way ... per pint.


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From: Hughes, B 
Subject: Re: Units of measure
Date: 26 Aug 2003 16:23:56
Message: <3f4bc1dc@news.povray.org>
"ingo" <ing### [at] tagpovrayorg> wrote in message
news:Xns### [at] povrayorg...
> in news:3f4b9573@news.povray.org Warp wrote:
>
> >   Can you tell with a straight face "a mile is 63360 inches, 5280 feet
> > and 1760 yards, and this system is not stupid"?
>
> t's a matter of perception. Why would you need to do these conversions? If
> you want to give a certain length or distance it depends on the size what
> kind of unit you choose to express this size in. A baseball field is 120
> yards deep, a distance to travel is expressed in miles, small dimensions
> are in mills or inches, the hight of a plane in feet. Where to put the
> moment that you change from one to another unit is a matter of instict or
> lessons learned, but not completely arbitraily. In this regard the system
> is not different to our metric system. Just that the points of change are
> a bit sharper, it's 90 cm and 1.20 meter. But we also have halve a
> kilometer and 900 meters. A moutain we measure in meters, not kilometers.
>
> Ingo
>  ... who only orders his beer in a non metric way ... per pint.

Hmmmm. When I was a kid I thought clocks ought to only go to ten, not
twelve, and time work in a metric sort of way. I also believed the metric
system must be far superior a system of units due to the inherent
simplicity, being based on tens too, you know.
So in this respect I might differ from Ken's viewpoint. However, maybe by
being American or something, I can't let go of the rather stupid 12 inches
in a foot, 3 feet in a yard, 52830 feet in a mile, etc. I never liked
fractions of inches either... but I just can't ignore the aggravation of
converting to millimeters and centimeters simply because we *must* do the
converting here in the USA. Like we can't break away from the so-called
standard units. Only thing I know of that seems so completely metric is the
larger beverage containers (Coca-Cola, Pepsi, etc.) sold in liters not
quarts or gallons. Now there's got to be something stupid there!
 :-D
P.S. it's things like this web page's answer to why a mile is a mile that
makes me wonder even more about this stuff.
http://www.coolquiz.com/trivia/explain/docs/mile.asp

Bob H.


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From: S McAvoy
Subject: Re: Units of measure
Date: 26 Aug 2003 17:32:43
Message: <7fknkv4hpqka5t2p16b6qlvff61glcfrm4@4ax.com>
On Tue, 26 Aug 2003 15:23:42 -0500, "Hughes, B." <omn### [at] charternet> wrote:

>P.S. it's things like this web page's answer to why a mile is a mile that
>makes me wonder even more about this stuff.
>http://www.coolquiz.com/trivia/explain/docs/mile.asp
>
>Bob H.

Try this one for size
http://www.baronage.co.uk/bphtm-02/moa-10.html

Regards
        Stephen


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From: Alan Smith
Subject: Re: Units of measure
Date: 26 Aug 2003 20:00:12
Message: <3f4bf48c@news.povray.org>
You might also be interested in trying Googles flexible conversion thingy...
try Googling ... "10 km / 3 furlongs" for example.

Alan Smith


"S McAvoy" <mca### [at] aolcom> wrote in message
news:7fknkv4hpqka5t2p16b6qlvff61glcfrm4@4ax.com...
> On Tue, 26 Aug 2003 15:23:42 -0500, "Hughes, B." <omn### [at] charternet>
wrote:
>
> >P.S. it's things like this web page's answer to why a mile is a mile that
> >makes me wonder even more about this stuff.
> >http://www.coolquiz.com/trivia/explain/docs/mile.asp
> >
> >Bob H.
>
> Try this one for size
> http://www.baronage.co.uk/bphtm-02/moa-10.html
>
> Regards
>         Stephen


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From: Ken
Subject: Re: Units of measure
Date: 26 Aug 2003 22:23:36
Message: <3F4C15B3.4592A5A7@pacbell.net>
Warp wrote:
> 
> Ken <tyl### [at] pacbellnet> wrote:
> > I'm all for it as long as it is in inches, feet and yards rather than that
> > stupid metric system.
> 
>   I don't understand why the American system would be better and more
> logical.

:)

(~: I really should add more smileys to my posts. I am absolutely against :~)
(~: assigning specific units in POV-Ray. If you want to argue the merits of :~)
(~: one measurement system over another I would be more than happy to continue :~)
(~: this in the off-topic group and even then don't expect me to take it too :~)
(~: seriously. As an Engineer I use both systems interchangably without even :~)
(~: thinking about. In this regard I am really not all that biased except :~)
(~: when it I need some amusement and think it's time to yank your chain :~)

:)

F'ups set :)

:)

-- 
Ken Tyler :)

:)


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