Thanks for the welcome, and you're absolutely right - it does say to
remove the pigment blocks in the declared tori and cylinders as you say.
Which is interesting, because I double and tripple checked the documents
before I decided it was worth posting as a possible bug!

  This suggests that the problem is that the instruction is embedded in the
text and there is no example showing the change, whereas I did recall that
many of the other examples throughout the tutorial would show code blocks
for all the changes and not just for the newest additions.

  As a User Experience professional, I would suggest that although the
documentation is technically correct, it would be more obvious what the user
was expected to do (and also far less likely that a user might "miss" that
particular required step) I would suggest combinging the textual description
for the removal of pigments, the declaration of "Chain_Gold" and changing
the previously defined union to a declaration for "Link" with the
"Chain_Gold" texture added, and then showing an example that includes every
code block that was just added or required changes to according to the
steps:

EXAMPLE:

We render this [Ed: the script developed up to that point] and voila! A
single link of a chain. But we aren't done yet! Whoever heard of a green
chain? We would rather use a nice metallic color instead. First, we remove
any pigment blocks in the declared tori and cylinders. Then we add a
declaration for a golden texture just before the union that creates the
link.  Finally, we add the texture to the union and declare it as a single
link:
  #declare Half_Torus = difference {
    torus {
      4,1
      sturm
      rotate x*-90  // so we can see it from the top
    }
    box { <-5, -5, -1>, <5, 0, 1> }
  }
  #declare Chain_Segment = cylinder {
    <0, 4, 0>, <0, -4, 0>, 1
  }
  #declare Chain_Gold = texture {
    pigment { BrightGold }
    finish {
      ambient .1
      diffuse .4
      reflection .25
      specular 1
      metallic
    }
  }
  #declare Link = union {
    object {
      Half_Torus
      translate y*Torus_Translate/2
    }
    object {
      Half_Torus
      rotate Flip_It_Over
      translate -y*Torus_Translate/2
    }
    object {
      Chain_Segment
      translate x*Torus_Translate/2
    }
    object {
      Chain_Segment
      translate -x*Torus_Translate/2
    }    texture { Chain_Gold }
  }
END EXAMPLE

  This would be much easier for a user to understand, because the results of
all the steps mentioned in the text are now made visible in the example. :-)

  Anyway -- thanks also for the tip about needing an "open" keyword -- if
I'd thought to take a look at the Language Reference for the sor shape I
might have thought to try that, but I hadn't quite gotten past the "follow
the tutorial" stage yet, so it never occured to me. :-)

   I do hope something gets posted to the official bugreports list about
this ommission though... otherwise you can expect lots of newbies to notice
and bring up the issue!

Jenni

--
Jenni A. M. Merrifield
-=> strawberryJAMM <=-
strawberry @ jamm.com

"hughes b" <omn### [at] charternet> wrote in message
news:3d33c5bc$1@news.povray.org...
> Hi and welcome Jenni.
>
> The gold chain script is supposed to undergo a change during creation.
> Looking it up, I quote from there at section 3.2.5 Torus Object (about 2/3
> way down):
>
> "We render this and voila! A single link of a chain. But we aren't done
yet!
> Whoever heard of a green chain? We would rather use a nice metallic color
> instead. First, we remove any pigment blocks in the declared tori and
> cylinders. Then we add the following before the union:"
>
> Unless there's another place in the Doc I didn't see with that
torusdemo.pov
> script which is in error it seems okay to me.
>
> Now, about that sor thing. Gee... well, I sure thought that had been fixed
> up in the Doc long ago. Maybe it had been and was redone wrong again. I
> believe the keyword open should be there. If I had a previous version
handy
> I'd take a look, but I don't just now.
>
>
>

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