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From: St 
Subject: Help needed with Lissajous Knot
Date: 31 Dec 2002 07:09:54
Message: <3e118912@news.povray.org>
Hi everyone,

      Firstly, a very happy New Year to you all. I hope it's a good
one for all of you.

   Ok, can someone help me out here? I can't seem to get Lutz-Peter
Hooges' Lissajous Knot Generator to work. PoV3.5 reports that a
'numeric expression' is expected, but ^ found instead. This happens
with #macro method3, but if I change the method, it happens with that
corresponding method too.

      The Generator can be found here:
http://news.povray.org/povray.text.scene-files/20596/135690/#135690

     Where am I going wrong with this?

      Thanks for any help.

      ~Steve~


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From: Ib Rasmussen
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 07:29:15
Message: <3E118DC6.6040800@ibras.dk>
St. wrote:

>    Ok, can someone help me out here? I can't seem to get Lutz-Peter
> Hooges' Lissajous Knot Generator to work. PoV3.5 reports that a
> 'numeric expression' is expected, but ^ found instead.35690/#135690


I don't think ^ is a legal operator in Pov. Try the pow(a, b) function 
instead.

/Ib


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From: Lutz-Peter Hooge
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 07:31:45
Message: <3e118e31$1@news.povray.org>
St. <dot### [at] dotcom> wrote:

> Hooges' Lissajous Knot Generator to work. PoV3.5 reports that a
> 'numeric expression' is expected, but ^ found instead.

I made that script with a beta verison of 3.5 wich did still include the 
"^" Operator.

Just replace any a^b in the script with pow(a,b), then it should work as 
expected.

Lutz-Peter


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From: St 
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 08:21:04
Message: <3e1199c0@news.povray.org>
"Ib Rasmussen" <ib### [at] ibrasdk> wrote in message
news:3E1### [at] ibrasdk...
 and...
"Lutz-Peter Hooge" <lpv### [at] gmxde> wrote in message
news:3e118e31$1@news.povray.org...

> I made that script with a beta verison of 3.5 wich did still include
the
> "^" Operator.

      Ah, sorry, I should have guessed. I thought it looked different
from your first one.

>
> Just replace any a^b in the script with pow(a,b), then it should
work as
> expected.

   Many thanks both, but I still don't know where to change the
script. (I've tried everything apart from the correct places of
course...)  ;)

  Could you show me where and how please?

  Here's the part:

 #macro Method3(T)
 <
  R*sin(A*T)*sin(B*T)^exp_X,
  R*sin(A*T)*cos(B*T)^exp_Y,
  R*sin(A*T)^exp_Z
 >
#end

   ~Steve~




>
> Lutz-Peter


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From: Ib Rasmussen
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 08:32:09
Message: <3E119C83.8060702@ibras.dk>
St. wrote:

>   Could you show me where and how please?
> 
>   Here's the part:
> 
>  #macro Method3(T)
>  <
>   R*sin(A*T)*sin(B*T)^exp_X,
>   R*sin(A*T)*cos(B*T)^exp_Y,
>   R*sin(A*T)^exp_Z
>  >
> #end

That should be

  #macro Method3(T)
  <
   R*sin(A*T) * pow(sin(B*T), exp_X),
   R*sin(A*T) * pow(cos(B*T), exp_Y),
   pow(R*sin(A*T), exp_Z)
  >
 #end


if I understand it right. I haven't tested it, though.

/Ib


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From: St 
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 08:59:03
Message: <3e11a2a7@news.povray.org>
"Ib Rasmussen" <ib### [at] ibrasdk> wrote in message
news:3E1### [at] ibrasdk...

> That should be
>
>   #macro Method3(T)
>   <
>    R*sin(A*T) * pow(sin(B*T), exp_X),
>    R*sin(A*T) * pow(cos(B*T), exp_Y),
>    pow(R*sin(A*T), exp_Z)
>   >
>  #end
>
>
> if I understand it right. I haven't tested it, though.

      Thanks Ib!  :)  That works a treat!

       All the best.

      ~Steve~


>
> /Ib
>
>
>


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From: Tor Olav Kristensen
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 09:00:06
Message: <web.3e11a27556251e337d655a8f0@news.povray.org>
Ib Rasmussen wrote:
>
>St. wrote:
>
>>   Could you show me where and how please?
>>
>>   Here's the part:
>>
>>  #macro Method3(T)
>>  <
>>   R*sin(A*T)*sin(B*T)^exp_X,
>>   R*sin(A*T)*cos(B*T)^exp_Y,
>>   R*sin(A*T)^exp_Z
>>  >
>> #end
>
>That should be
>
>  #macro Method3(T)
>  <
>   R*sin(A*T) * pow(sin(B*T), exp_X),
>   R*sin(A*T) * pow(cos(B*T), exp_Y),
>   pow(R*sin(A*T), exp_Z)
>  >
> #end
>
>
>if I understand it right. I haven't tested it, though.

Ib, I think he is using the code Lutz-Peter Hooge
posted to povray.text.scene-files 8. Dec. 2001 for
his "Lissajou-Knot generator":

http://news.povray.org/povray.text.scene-files/20596/135690/#135690
http://news.povray.org/povray.binaries.images/20597/

And if that is so, then he should rewrite the
macro like this (for the final POV-Ray v3.5):


#macro Method3(T)

  <
    R*sin(A*T)*pow(sin(B*T), exp_X),
    R*sin(A*T)*pow(cos(B*T), exp_Y),
    R*pow(sin(A*T), exp_Z)
  >

#end


Tor Olav


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From: Ib Rasmussen
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 09:11:36
Message: <3E11A5C3.9010406@ibras.dk>
Tor Olav Kristensen wrote:

> And if that is so, then he should rewrite the
> macro like this (for the final POV-Ray v3.5):
> 
> 
> #macro Method3(T)
> 
>   <
>     R*sin(A*T)*pow(sin(B*T), exp_X),
>     R*sin(A*T)*pow(cos(B*T), exp_Y),
>     R*pow(sin(A*T), exp_Z)
>   >
> 
> #end


Oops, yes, the R should be outside the pow-function. Thanks.

/Ib


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From: St 
Subject: Re: Help needed with Lissajous Knot
Date: 31 Dec 2002 10:52:56
Message: <3e11bd58@news.povray.org>
"Ib Rasmussen" <ib### [at] ibrasdk> wrote in message
news:3E1### [at] ibrasdk...
>
>
> Tor Olav Kristensen wrote:
>
> > And if that is so, then he should rewrite the
> > macro like this (for the final POV-Ray v3.5):
> >
> >
> > #macro Method3(T)
> >
> >   <
> >     R*sin(A*T)*pow(sin(B*T), exp_X),
> >     R*sin(A*T)*pow(cos(B*T), exp_Y),
> >     R*pow(sin(A*T), exp_Z)
> >   >
> >
> > #end
>
>
> Oops, yes, the R should be outside the pow-function. Thanks.


   I've just tried both ways, and both work??

     ~Steve~

>
> /Ib
>
>


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From: St 
Subject: Re: Help needed with Lissajous Knot
Date: 7 Jan 2003 14:43:17
Message: <3e1b2dd5@news.povray.org>
"St." <dot### [at] dotcom> wrote in message news:3e11bd58@news.povray.org...
>
> "Ib Rasmussen" <ib### [at] ibrasdk> wrote in message
> news:3E1### [at] ibrasdk...
> >
> >
> > Tor Olav Kristensen wrote:

> > Oops, yes, the R should be outside the pow-function. Thanks.
>
>
>    I've just tried both ways, and both work??

       Well, both DO work, but I've just discovered that I can't use
Tors' (correct) way unless I translate the object again and I'm not
doing that because it took *AGES* to get it where it is now with Ibs'
way. (Sorry Ib).

    So I now I have a new problem and it may be connected with the
above but I'm not sure. In Lutz-Peters' code, right at the very end,
there is the 'no_shadow' comment and of course, it produces no
shadows, but if I comment it out, it still produces no shadows. The
only way I can get shadows back in the *whole* scene is by taking the
Lissajous Knot code out and the shadows come back again.

  Any ideas about what's causing this?

    ~Steve~


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