I've created simple addition to expressions - vector symmetry operator "@".

Syntax
  Vector @ SymmetryRefference
  SymmetryRefference : Vector | ox | oy | oz | xy | xz | yz

Instead of explanation just examples of usage and old equivalents

#local A=<7,3,4>;
#local B=A@xy; /* B=<A.x,A.y,-A.z> */
#local B=A@xz; /* B=<A.x,-A.y,A.z> */
#local B=A@yz; /* B=<-A.x,A.y,A.z> */
#local B=A@ox; /* B=<A.x,-A.y,-A.z> */
#local B=A@oy; /* B=<-A.x,A.y,-A.z> */
#local B=A@oz; /* B=<-A.x,-A.y,A.z> */
#local B=A@0; /* B=<-A.x,-A.y,-A.z> */
#local B=A@A; /* B=A */
#local B=A@(A-1) /* B=A-2 */

if there is any person interested in source to this patch I can upload it on
this news server.

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

On Thu, 10 May 2001 18:52:57 +0200, Wlodzimierz ABX Skiba wrote:
>I've created simple addition to expressions - vector symmetry operator "@".
>
>Syntax
>  Vector @ SymmetryRefference
>  SymmetryRefference : Vector | ox | oy | oz | xy | xz | yz
>
>Instead of explanation just examples of usage and old equivalents

Why a patch and not a macro?  

#macro VecSym(Vec, Sym)
  (vlength(Sym)?(2*vdot(Vec,Sym)/vlength(Sym)*Sym-Vec):(-Vec))
#end

Then you give it x instead of ox, y instead of oy, etc. and 
x+y instead of xy etc. 

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message

Ron Parker wrote in message ...
> On Thu, 10 May 2001 18:52:57 +0200, Wlodzimierz ABX Skiba wrote:
> >I've created simple addition to expressions - vector symmetry operator "@".
> >
> >Syntax
> >  Vector @ SymmetryRefference
> >  SymmetryRefference : Vector | ox | oy | oz | xy | xz | yz
>
> Why a patch and not a macro?
>
> #macro VecSym(Vec, Sym)
>  (vlength(Sym)?(2*vdot(Vec,Sym)/vlength(Sym)*Sym-Vec):(-Vec))
> #end
>
> Then you give it x instead of ox, y instead of oy, etc. and
> x+y instead of xy etc.


x and x+y has meaning of vectors in POV (center of symetry)
ox is not <1,0,0> but axis x
xy is not <1,1,0> but plane contained axes x and y
and patch becouse now I'm adding support for plane{}
#local B=A@plane{y 1 rotate C translate z}
than perhaps I remove xy, xz and yz planes

of course all these things are posible with current syntax and macros but it was
inspired by my current work and short sigs it was just too much for me to type
<-A.x,A.y,A.z> to change sign only for one coordinate

perhaps AT_TOKEN is wrong but it is only one free I found
and I wanted avoid ambiguity

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

Wlodzimierz ABX Skiba <abx### [at] abxartpl> wrote:

> of course all these things are posible with current syntax and
> macros but it was inspired by my current work and short sigs it was
> just too much for me to type <-A.x,A.y,A.z> to change sign only for
> one coordinate

Why not A*<-1,1,1>? Or A-2*x*A?


-- 
Christopher James Huff - chr### [at] maccom
Home Page: http://homepage.mac.com/chrishuff/
POV-Ray TAG e-mail: chr### [at] povrayorg
POV-Ray TAG web site: http://tag.povray.org/

Post a reply to this message

Chris Huff wrote in message <3afbc248@news.povray.org>...
>Wlodzimierz ABX Skiba <abx### [at] abxartpl> wrote:
> > of course all these things are posible with current syntax and
> > macros but it was inspired by my current work and short sigs it was
> > just too much for me to type <-A.x,A.y,A.z> to change sign only for
> > one coordinate
>
> Why not A*<-1,1,1>? Or A-2*x*A?


becouse it is longer than A@yz ;)

as I said I know all kind of symmetry are possible somehow
I just tried (succesfully) collect them to one way

A@0
A@B
A@xy
A@ox
A@plane{y 2 rotate z*30 translate 10}

I don't want pressure to use it. I just offered sharing if anybody find it
usefull.

If any person is also interested I've also added such extension

#local MyArray=array[4][4]{tranform{rotate 10*x translate z}}

which assigns matrix of transformation to array

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

Modifying the POV-Ray source code and thus making a patch can be cool
(I have made that, I know what I'm talking about :) ), but it's important
to be aware of one thing:

  If the exact same functionality can be made with an include file (usually
implemented as a #macro) without noticeable resource penalty (time, memory,
etc) nor compromise in easy-to-use, then the #macro is definitely the
right choice.

  Why?
  If this kind of thing is made by modifying the source code, it will only
cause more trouble than it's worth. It will also limit the functionality of
the new idea a lot.
  Adding new patches to a patch collection (such as MegaPov) or even the
official povray is usually a maintenance nightmare and a lot of work.
  Also the functionality of a patch is extremely fixed, ie. unmodifiable
(at least without having to modify the source code itself).

  A #macro, however, is much more versatile. You not only can use it, but
you can look how it is done, learn from it, modify it for your specific
needs, make your own version of it and so on. A #macro is much easier to
take (just download the include file from a website to your include
directory); you don't have to wait for someone to include it in MegaPov or
whatever. A #macro is also much less likely to have bugs than a patch.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

Post a reply to this message

Warp wrote in message <3afbd171@news.povray.org>...
> [cut]

I know all adventages of using macros becouse I always carefully read your
posts. Althought I prepared this for myself not for community and just offered
sharing if anybody has the same problem (less typing) like me. I'm not uploaded
this without ask becouse I didn't want "bring noise" to community. Also I coded
this with respect to rules of adding patch learned from MegaPOV source and my
patch could be off by commenting of one #define. Anyway thanks for lesson.

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

On Fri, 11 May 2001 09:04:59 +0200, Wlodzimierz ABX Skiba wrote:
>x and x+y has meaning of vectors in POV (center of symetry)
>ox is not <1,0,0> but axis x

But there's no difference.

>xy is not <1,1,0> but plane contained axes x and y

Okay, this part is different.  That would need another macro

>and patch becouse now I'm adding support for plane{}
>#local B=A@plane{y 1 rotate C translate z}

And that macro would happily do this part as well.

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message

On Fri, 11 May 2001 09:04:59 +0200, Wlodzimierz ABX Skiba wrote:
>inspired by my current work and short sigs it was just too much for me to type
><-A.x,A.y,A.z> to change sign only for one coordinate

Yeah, I thought about making patches to make it easier to make a really short 
sig too, but where's the fun in that?  That's like giving in to the dark side
and using the $ operator.

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message

Ron Parker wrote in message ...
> On Fri, 11 May 2001 09:04:59 +0200, Wlodzimierz ABX Skiba wrote:
> > x and x+y has meaning of vectors in POV (center of symetry)
> > ox is not <1,0,0> but axis x
>
> But there's no difference.

for geometry symmetry it is difference
I wanted translate symmetry from math to syntax
A=<3,2,3> symetry by x (<1,0,0>) -> A'=<-2,-2,-3>
A=<4,2,3> symetry by axis ox -> A'=<4,-2,-3>

> > and patch becouse now I'm adding support for plane{}
> > #local B=A@plane{y 1 rotate C translate z}
>
> And that macro would happily do this part as well.


and it is as easy to understand and code ?

ABX
--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

Ron Parker wrote in message ...
> On Fri, 11 May 2001 09:04:59 +0200, Wlodzimierz ABX Skiba wrote:
> >inspired by my current work and short sigs it was just too much for me to
type
> ><-A.x,A.y,A.z> to change sign only for one coordinate
>
> Yeah, I thought about making patches to make it easier to make a really short
> sig too, but where's the fun in that?

I never said I want use it for sigs. I just was inspired by them for my current
scene.


--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

On Fri, 11 May 2001 15:01:28 +0200, Wlodzimierz ABX Skiba wrote:
>Ron Parker wrote in message ...
>> On Fri, 11 May 2001 09:04:59 +0200, Wlodzimierz ABX Skiba wrote:
>> >inspired by my current work and short sigs it was just too much for me to
>type
>> ><-A.x,A.y,A.z> to change sign only for one coordinate
>>
>> Yeah, I thought about making patches to make it easier to make a really short
>> sig too, but where's the fun in that?
>
>I never said I want use it for sigs. I just was inspired by them for my current
>scene.

<voice type="bad foghorn leghorn impression">
That was a joke, son.
</voice>

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message

On Fri, 11 May 2001 14:59:37 +0200, Wlodzimierz ABX Skiba wrote:
>Ron Parker wrote in message ...
>> On Fri, 11 May 2001 09:04:59 +0200, Wlodzimierz ABX Skiba wrote:
>> > x and x+y has meaning of vectors in POV (center of symetry)
>> > ox is not <1,0,0> but axis x
>>
>> But there's no difference.
>
>for geometry symmetry it is difference
>I wanted translate symmetry from math to syntax
>A=<3,2,3> symetry by x (<1,0,0>) -> A'=<-2,-2,-3>
>A=<4,2,3> symetry by axis ox -> A'=<4,-2,-3>

Ah, well the macro I gave mirrors the first vector about the axis defined 
by the second vector (unless the second vector is zero.)  To mirror around
a point, you'd need to do

#macro PtSym( Vec, Pt )
  (2*Pt-Vec)
#end

>> And that macro would happily do this part as well.
>
>and it is as easy to understand and code ?

Once someone else has written the macro, probably easier to understand, and
only a few more keystrokes to code.  Making it have the syntax of an operator
is fun, but it quickly leads to code that looks like line noise.  I can see
more use for having shorter versions of vnormalize, vcross, and vdot than I 
can for vector symmetry, but that's not likely to happen either (though maybe
one could make an argument for |V| to mean vnormalize...)

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message

Ron Parker wrote in message ...
> <voice type="bad foghorn leghorn impression">
> That was a joke, son.
> </voice>


and smile was in the header ? :-)

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

Ron Parker wrote in message ...
> Ah, well the macro I gave mirrors the first vector about the axis defined
> by the second vector (unless the second vector is zero.)  To mirror around
> a point, you'd need to do
>
> #macro PtSym( Vec, Pt )
>  (2*Pt-Vec)
> #end

Yes, I know, it's part of my patch.
Please don't show me any more examples of how code this - I know it!
Also I know that we don't need dot operator for vector.
Just vdot(V,x) instead of V.x
We don't need A?B:C becouse #if(A)B#else C #end works fine
I just needed it becouse of less typing and more natural for me

> it quickly leads to code that looks like line noise.

just like our sigs

> (though maybe
> one could make an argument for |V| to mean vnormalize...)

good idea

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

On Fri, 11 May 2001 16:25:37 +0200, Wlodzimierz ABX Skiba wrote:
>Please don't show me any more examples of how code this - I know it!

Perhaps you didn't notice everyone else who's reading this.  I just did
the macros to show that it can be done; in the past when I've claimed that
something was more easily done with macros than with a patch, I've gotten
a lot of static from people who want me to put up or shut up, so now I 
give examples with my claims.  Don't take it personally.

>Also I know that we don't need dot operator for vector.
>Just vdot(V,x) instead of V.x
>We don't need A?B:C becouse #if(A)B#else C #end works fine
>I just needed it becouse of less typing and more natural for me

But my point was that it's not natural.  "@" doesn't mean anything like
that in any other language, and saying "A at B" in english doesn't convey
any sort of symmetry meaning, so the syntax is highly unnatural.  Those
other operators might be unnatural, too, to someone with no experience with
other languages, but at least they makes sense to some of us.

>> it quickly leads to code that looks like line noise.
>
>just like our sigs

Not even close.  Both of us have sigs that consist mostly of what looks
like English words, but something like (<4,3,2>@x+y@<5,6.7,8>).z really
does look like noise.

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message

Ron Parker <ron### [at] povrayorg> wrote:
: one could make an argument for |V| to mean vnormalize...)

  I suppose you mean vlength?


-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

Post a reply to this message

Ron Parker wrote in message ...
> Don't take it personally.

now that's more clear :-)

> > Also I know that we don't need dot operator for vector.
> > Just vdot(V,x) instead of V.x
> > We don't need A?B:C becouse #if(A)B#else C #end works fine
> > I just needed it becouse of less typing and more natural for me
>
> But my point was that it's not natural.  "@" doesn't mean anything like
> that in any other language

I expleined somwhere at begining that I get "@" becouse it was only free - I
want get "|" as symbol of mirror but it was reserved for other operations

> and saying "A at B" in english doesn't convey any sort of symmetry meaning

I don't like it too

> > just like our sigs
>
> Not even close.  Both of us have sigs that consist mostly of what looks
> like English words, but something like (<4,3,2>@x+y@<5,6.7,8>).z really
> does look like noise.


what about :

x / |x| + ( x $X = ( x @ x ) . x ^ ( x * x ) ;)

--
#macro Sig(A,B,X)_(A,B)_(B,X)_(X,A)#end#macro _(A,B)cylinder{<A.x,A.y,3>,<B.u,
B.v,3>.1,9}#end global_settings{max_trace_level 9}light_source{0 1}camera{up y
*4right-3*x}blob{_(<3,1>,<1,-5>)_(<2,-2>,<4,-2>)Sig(x,<-1,1.5>,<1,3>)_(z-1,z-4
)pigment{rgb 1}}box{-3 3pigment{rgb 0}finish{reflection 1}hollow} // POV-Ray31

Post a reply to this message

On 11 May 2001 11:04:05 -0400, Warp wrote:
>Ron Parker <ron### [at] povrayorg> wrote:
>: one could make an argument for |V| to mean vnormalize...)
>
>  I suppose you mean vlength?

Of course.  I was thinking vlength but wrote vnormalize.  D'oh!

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbf 1}hollow interior{media{emission 3-T}}}#end 
Z(-x-x.2x)camera{location z*-10rotate x*90normal{bumps.02scale.05}}

Post a reply to this message