Hi,

I'm trying to create sort of metal shielded cables by placing lathed shapes along a
spline.
I've been using Rune's Spline_Trans macro, which works fine, except that I want to be
able to
place objects equidistant along the spline. Is there a macro out there that will allow
me to
do this? Chris Colefax's Spline.mcr for 3.1 won't run, giving me a parse error, and I
think
that would do what I want. Has it been updated for 3.5?

Any help greatly appreciated. i don't want to have to abandon this idea and use
sphere_sweeps
for the cables.

Andy Cocker

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On Thu, 5 Sep 2002 11:40:31 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
wrote:
> Any help greatly appreciated. i don't want to have to abandon this idea and use
sphere_sweeps
> for the cables.

http://news.povray.org/qr7aeugkvt07m6obnchs3hben663jbnkit%404ax.com

ABX

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Many thanks.

Andy

"ABX" <abx### [at] abxartpl> wrote in message
news:pcdenusb2i02trqkr5k2afkdo7d92jbcf9@4ax.com...
> On Thu, 5 Sep 2002 11:40:31 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
> wrote:
> > Any help greatly appreciated. i don't want to have to abandon this idea and use
sphere_sweeps
> > for the cables.
>
> http://news.povray.org/qr7aeugkvt07m6obnchs3hben663jbnkit%404ax.com
>
> ABX

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Hi ABX,

Ok, I've just spent an hour or two trying to get these macros to work, but the problem
is that
I just don't understand how to use them. I had hoped to find a pre-written macro that
would
allow me to declare my spline, declare my object, declare the number of objects, and
the macro
does the rest, orienting the objects to the spline, and placing them at equal
distances along
it.

The thing is, I'm annoyed at myself for not being able to understand your macros. I've
been
POV-ing for years, and yet still come unstuck regularly. I would really appreciate it
if you
could provide any help here, and show me how to use the macros.

I'll need some way of orienting the objects to the spline, so I'll need another macro
to do
that?

The temporary code below uses Rune's Spline_Trans macro.

#declare MySpline =
spline {
   cubic_spline
 -1,<-1,1,0>,
 0,<0,1,0>,
 0.3, <2,0.7,-2>,
 0.6,<3,-0.8,-3>,
 0.85,<0,-0.8,-3.5>,
 1,<-1,-0.8,-3.72>,
 1.1,<-2,-0.8,-3.75>
}

#declare MyObject =
cone {<0,0,0>,0.2,<0,0,.2>,0.15}

#declare Count=0;
#while (Count<=0.95)
object { MyObject pigment { rgb <1,.3,.7>}
        Spline_Trans(MySpline, Count, y, 0.1, 0.1)
        //MySpline(Count)
        }
#declare Count=Count+.025;
#end

Thanks.

Andy Cocker


"ABX" <abx### [at] abxartpl> wrote in message
news:pcdenusb2i02trqkr5k2afkdo7d92jbcf9@4ax.com...
> On Thu, 5 Sep 2002 11:40:31 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
> wrote:
> > Any help greatly appreciated. i don't want to have to abandon this idea and use
sphere_sweeps
> > for the cables.
>
> http://news.povray.org/qr7aeugkvt07m6obnchs3hben663jbnkit%404ax.com
>
> ABX

Post a reply to this message

On Thu, 5 Sep 2002 14:24:01 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
wrote:
> Hi ABX,

Hi again :-)

> Ok, I've just spent an hour or two trying to get these macros to work

Yes, there was two mistakes I somehow left and there was actually one (already
know) 3.5 bug influence. Try below complete scene:

#include "transforms.inc"
#include "shapes.inc"
#include "strings.inc"

#macro Time_To_Length_Converter(Spline,Min,Max,Accuracy)
  #local Conversion=function{spline{
    #local Last=Spline(Min);
    #local Length=0;
    #local C=Min;
    #while (C<=Max)
      #local C=min(C,Max);
      #local Point=Spline(C);
      #local Length=Length+vlength(Point-Last);
      #local Last=Point;
      C , <1,0,0>*Length
      #local C=C+Accuracy;
    #end
  }};
  function(T){Conversion(T).x}
#end

#macro Spline_With_Linear_Movement(Spline,Min,Max,Accuracy)
  spline{
    #local Last=Spline(Min);
    #local Length=0;
    #local C=Min;
    #while (C<=Max)
      #local C=min(C,Max);
      #local Point=Spline(C);
      #local Length=Length+vlength(Point-Last);
      #local Last=Point;
      Length , Point+<0,0,0>
      #local C=C+Accuracy;
    #end
  }
#end

#declare MySpline = spline {
   cubic_spline
   -1,<-1,1,0>,
   0,<0,1,0>,
   0.3, <2,0.7,-2>,
   0.6,<3,-0.8,-3>,
   0.85,<0,-0.8,-3.5>,
   1,<-1,-0.8,-3.72>,
   1.1,<-2,-0.8,-3.75>
  }

#declare MySplineLinear = Spline_With_Linear_Movement(MySpline,0,1,0.001);
#declare f_MySplineLength = Time_To_Length_Converter(MySpline,0,1,0.001);
#declare MySplineLength = f_MySplineLength(1);

#declare MyObject = cone {0 .2 <0,0,.2> 0.15 pigment{rgb 1}};

#declare Step=MySplineLength/20;

#declare All=union{
  #declare Count=0;
  #while (Count<=MySplineLength-Step)
    object {
      MyObject
      pigment { rgb <1,.3,.7>}
      Spline_Trans(MySplineLinear, Count, y, 0.1, 0.1)
    }
    #declare Count=Count+Step;
  #end
  rotate x*90
}

object{
  Center_Object(All,1)
  translate z*5
}

background{1}
light_source{y*100 1}


ABX

Post a reply to this message

Hi once more :-)

Thankyou. I shall try this and hopefully I'll manage ok.

...but I 'may' be back.. ;-)

All the best,

Andy Cocker

"ABX" <abx### [at] abxartpl> wrote in message
news:ttoenucoq6fcgkun57la24s9ia4ij5o573@4ax.com...
> On Thu, 5 Sep 2002 14:24:01 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
> wrote:
> > Hi ABX,
>
> Hi again :-)
>
> > Ok, I've just spent an hour or two trying to get these macros to work
>
> Yes, there was two mistakes I somehow left and there was actually one (already
> know) 3.5 bug influence. Try below complete scene:
>
> #include "transforms.inc"
> #include "shapes.inc"
> #include "strings.inc"
>
> #macro Time_To_Length_Converter(Spline,Min,Max,Accuracy)
>   #local Conversion=function{spline{
>     #local Last=Spline(Min);
>     #local Length=0;
>     #local C=Min;
>     #while (C<=Max)
>       #local C=min(C,Max);
>       #local Point=Spline(C);
>       #local Length=Length+vlength(Point-Last);
>       #local Last=Point;
>       C , <1,0,0>*Length
>       #local C=C+Accuracy;
>     #end
>   }};
>   function(T){Conversion(T).x}
> #end
>
> #macro Spline_With_Linear_Movement(Spline,Min,Max,Accuracy)
>   spline{
>     #local Last=Spline(Min);
>     #local Length=0;
>     #local C=Min;
>     #while (C<=Max)
>       #local C=min(C,Max);
>       #local Point=Spline(C);
>       #local Length=Length+vlength(Point-Last);
>       #local Last=Point;
>       Length , Point+<0,0,0>
>       #local C=C+Accuracy;
>     #end
>   }
> #end
>
> #declare MySpline = spline {
>    cubic_spline
>    -1,<-1,1,0>,
>    0,<0,1,0>,
>    0.3, <2,0.7,-2>,
>    0.6,<3,-0.8,-3>,
>    0.85,<0,-0.8,-3.5>,
>    1,<-1,-0.8,-3.72>,
>    1.1,<-2,-0.8,-3.75>
>   }
>
> #declare MySplineLinear = Spline_With_Linear_Movement(MySpline,0,1,0.001);
> #declare f_MySplineLength = Time_To_Length_Converter(MySpline,0,1,0.001);
> #declare MySplineLength = f_MySplineLength(1);
>
> #declare MyObject = cone {0 .2 <0,0,.2> 0.15 pigment{rgb 1}};
>
> #declare Step=MySplineLength/20;
>
> #declare All=union{
>   #declare Count=0;
>   #while (Count<=MySplineLength-Step)
>     object {
>       MyObject
>       pigment { rgb <1,.3,.7>}
>       Spline_Trans(MySplineLinear, Count, y, 0.1, 0.1)
>     }
>     #declare Count=Count+Step;
>   #end
>   rotate x*90
> }
>
> object{
>   Center_Object(All,1)
>   translate z*5
> }
>
> background{1}
> light_source{y*100 1}
>
>
> ABX

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Thankyou so much.. it works perfectly.

All the best,

Andy Cocker

Post a reply to this message

On Thu, 5 Sep 2002 11:40:31 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
wrote:
> i don't want to have to abandon this idea and use sphere_sweeps
> for the cables.

BTW, I'm currently working on completly rewrite of sphere_sweep module. I hope
in my implementation they will be much better. I use bounding hierarchy for
segments, optimized and correct bounding boxes, component texturing, shared
memory for copies etc, etc.

ABX

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Already sent this to Andy, but thought I should post it here.

To get Chris Colefax's Spline Macro working with 3.5, all you need to do is
a global find an replace and change Chris macro vstr (now a reserved keyword
in 3.5), to something else, such as vvstr.

Bingo!

--
http://www.manhog.freeuk.com/
ICQ 114025688
Long live Politzania

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ABX wrote:
> On Thu, 5 Sep 2002 11:40:31 +0100, "Andrew Cocker" <mai### [at] andrewcockercouk>
> wrote:
> 
>>i don't want to have to abandon this idea and use sphere_sweeps
>>for the cables.
> 
> 
> BTW, I'm currently working on completly rewrite of sphere_sweep module. I hope
> in my implementation they will be much better. I use bounding hierarchy for
> segments, optimized and correct bounding boxes, component texturing, shared
> memory for copies etc, etc.
> 
> ABX

Hear hear! This is very welcome news!

I played with sphere_sweeps recently and it was my initial experience
that manual bounding was pretty much required if you wanted to stay
sane. They are such a promising new primitive it is good to hear that
better auto-bounding is being worked on.

-- 
@C[$F];
The Silver Tome ::  http://www.silvertome.com
"You may sing to my cat if you like..."

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