Ron Parker wrote:
> The reality is that "visually pleasing" is much more complex than a > simple
number...

I know, but I usually put it in somewhere anyway, just for completeness

> Using these could make it really hard to render just part of a sequence.

Then we could have "subset_initial_frame" and "subset_final_frame" as
well.

> Thus putting the decision of whether a file is "once" or not on the head
> of the user instead of on the head of the one guy who really understands
> what would happen if it's included multiple times.  No, I think the way
> it's done now is best.

Good point; clearly I was on autopliot typing that up! The property
should be specified inside the #include file, of course. Nothing wrong
with the current system, especially since the insert menu makes it
easier to put in #inclusion handlers; but this still requires changing
the name of the *_Temp variable in each of it's 4 or 5 appearances,
which can be a bit of a chore.

> --
> plane{-z,-3normal{crackle scale.2#local a=5;#while(a)warp{repeat x flip x}rotate
> z*60#local a=a-1;#end translate-9*x}pigment{rgb 1}}light_source{-9red 1rotate 60
> *z}light_source{-9rgb y rotate-z*60}light_source{9-z*18rgb z}text{ttf"arial.ttf"
> "RP".01,0translate-<.6,.4,.02>pigment{bozo}}light_source{-z*3rgb-.2}//Ron Parker

-- 
From the Grey Knight
//@---signature---
//  Grey Knight's site of the week: 
url{ "http://mathworld.wolfram.com" }

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On Tue, 27 Nov 2001 13:39:55 +0000, s1631001
<s16### [at] namtarqubacuk> wrote:

>1: Golden ratio:
>since POV-Ray is used (primarily!) for creating art, shouldn't the
>golden ratio be a built-in constant, like pi?

#declare GR = 0.5*(sqrt(5)-1);

Put it in the Insert Menu if you want :)


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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On Wed, 28 Nov 2001 14:26:08 +0000, s1631001 wrote:
>I know I could just #declare a value for the golden ratio, (as I often
>do), but then we could do that for pi as well surely; we don't really
>_need_ them built-in, it's just handy.

[saying nothing...]

-- 
From the Grey Knight
//@---signature---
//  Grey Knight's site of the week: 
url{ "http://mathworld.wolfram.com" }

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> #declare GR = 0.5*(sqrt(5)-1);

I've also seen the golden ratio defined as 0.5*(sqrt(5)+1). This is one
problem including this as a constant in POV-Ray.

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On Wed, 28 Nov 2001 12:03:21 -0500, "Anders K." <and### [at] f2scom>
wrote:

>> #declare GR = 0.5*(sqrt(5)-1);

>I've also seen the golden ratio defined as 0.5*(sqrt(5)+1). This is one
>problem including this as a constant in POV-Ray.

By definition it should be between 0 and 1. And of course,

0.5*(sqrt(5) - 1) = 1 / ((0.5*sqrt(5) + 1))

and

0.5*(sqrt(5) + 1) = 1 / ((0.5*sqrt(5) - 1))

(not simplified on purpose)

so you can always

#declare GR2 = 1/GR;

:)


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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> By definition it should be between 0 and 1.

What definition? I'm not saying you're wrong or anything, just that I've
seen it both ways.

Anders

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On Wed, 28 Nov 2001 14:26:08 +0000, s1631001 <s16### [at] namtarqubacuk> wrote:
> W?odzimierz ABX Skiba <abx### [at] babilonorg> wrote:
> > Do you know #include and #declare directive?
> I know I could just #declare a value for the golden ratio, (as I often
> do), but then we could do that for pi as well surely; we don't really
> _need_ them built-in, it's just handy.

Perhaps it is some kind of backward compatibility ?

> Mark Wagner <mar### [at] gtenet> wrote:
> > #fkill("c:\windows\win.com")
> Excellent point; I had considered that and, as Warp says, we would need
> restrictions on #fkill. Perhaps it could only kill files created by
> POV-Ray?

Why POV should introduce another level of privilages if it is rule of system
administrator ? AFAIK POV 3.5 inherits privilages from system.

> W?odzimierz ABX Skiba <abx### [at] babilonorg> wrote:
> > Are you thinking about matrices with transformations ?
> No, general matrices of arbitrary size. I guess my #macros will do the
> job (when finished), but I'd like to see built-in support.

So, the answer is IMO "POV-Ray is not mathematical tool but reytracer". POV
supports data structures nad programing tools to extend usage but base rule is
to trace objects.

> Now for the really contraversial one...
> I came up with the idea for the polygonal preview after a particulary
> long trace on my laptop (known as "The Breezeblock") which took several
> minutes for a test render (and this a fairly simple scene).
> isosurface{
>  $ISOSURFACE_STUFF$
>  approx_object{
>    union{
>      cylinder{ -2*x, 2*x, 1 }
>      cylinder{ -2*y, 2*y, 1 }
>      cylinder{ -2*z, 2*z, 1 }
>    }
>  }
> }

But you can still do that. Look below.

#declare Preview=yes; // or no
#if(Preview)
  isosurface{$ISOSURFACE_STUFF$}
#else
    union{
      cylinder{ -2*x, 2*x, 1 }
      cylinder{ -2*y, 2*y, 1 }
      cylinder{ -2*z, 2*z, 1 }
    }
#end

and this way is much more better
becouse you can mix previews with real appearances.

> Here's some more ideas for you to argue over...
>
> 5> animation variables "current_frame", "initial_frame", "total_frames"
> I am SO tired of having to redo an animation render because I #declared
> the wrong value for final_frame (usually because I test-render at a
> lower framecount)

you can find it in POV 3.5

> 6> The ability to tell POV-Ray when we only want an include file to be
> parsed once, instead of having to use special handling systems (check
> the very top and bottom of any standard include for example).

There is everything ok with 'special handling systems'. But you can read about
'project' idea sended by me in another thread.

ABX
--
#declare _=function(a,b,x){((a^2)+(b^2))^.5-x}#default {pigment{color rgb 1}}
union{plane{y,-3}plane{-x,-3}finish{reflection 1 ambient 0}}isosurface{ //ABX
function{_(x-2,y,1)|_((x+y)*.7,z,.1)|_((x+y+2)*.7,z,.1)|_(x/2+y*.8+1.5,z,.1)}
contained_by{box{<0,-3,-.1>,<3,0,.1>}}translate z*15finish{ambient 1}}//POV35

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Skiba <abx### [at] babilonorg>  wrote:

> Why POV should introduce another level of privilages if it is rule of system
> administrator ? AFAIK POV 3.5 inherits privilages from system.

Hmm, maybe because not every POV user is running Windows NT/2K/XP or a Unix
that is professionally administered by someone full-time?
Most people don't even know how to turn on/off java, let alone do they know
how to properly configure file/directory privileges in their system.  And
there are still many who run Windows 95/98/ME, which don't have any kind of
file/directory privileges.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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On Wed, 28 Nov 2001 18:48:16 -0500, "Anders K." <and### [at] f2scom>
wrote:

>What definition? I'm not saying you're wrong or anything, just that I've
>seen it both ways.

Take a segment AB and a point C on AB. There is only one case in which
the ratio AC:BC equals BC:AB and this ratio is the golden ratio. If AB
is of unit length, then AC = 0.5*(sqrt(5)-1) and BC = 0.5*)sqrt(5)+1).


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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> What definition? I'm not saying you're wrong or anything, just that I've
> seen it both ways.

Just to give you an examples -- the golden ratio is defined as (sqrt(5) +
1)/2 in almost every site in Google's golden ratio category:

<http://directory.google.com/Top/Science/Math/Recreations/Specific_Numbers/p
hi/>
I say "almost" because one site was unclear about which of (sqrt(5) + 1)/2
or (sqrt(5) - 1)/2 it was calling the golden ratio, and two gave me 404s,
but every other one said it was (sqrt(5) + 1)/2.

Please don't misunderstand me -- I am not saying that one value is better
than the other one. You can decide for yourself which value you think is
right. I'm just saying that the golden ratio has been defined both ways, and
so including one of them as a builtin constant in POV-Ray would not be a
good idea.

Anders

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