Go easy on me... 8^)  I was looking at the knot thinking it could be done
with torus sections.  It can't quite, so I cheated...

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Jon Buller spake:

> Go easy on me... 8^)  I was looking at the knot thinking it could be done
> with torus sections.  It can't quite, so I cheated...

That's some RSOCP image...!

-- 
Stefan Viljoen
Software Support Technician / Programmer
Polar Design Solutions

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"Jon Buller" <jon### [at] bullersnet> wrote:
> Go easy on me... 8^)  I was looking at the knot thinking it could be done
> with torus sections.  It can't quite, so I cheated...

The first time I ever tried to build this figure I had no idea how to go
about calculating it, so I too tried using torus sections... tricky, and
only partially successful! (I was only 13 at the time...) Much easier to
calculate it, in my opinion.

Yours looks really good though :)

Bill

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> "Jon Buller" <jon### [at] bullersnet> wrote:
> > Go easy on me... 8^)  I was looking at the knot thinking it could be done
> > with torus sections.  It can't quite, so I cheated...
>
> The first time I ever tried to build this figure I had no idea how to go
> about calculating it, so I too tried using torus sections... tricky, and
> only partially successful! (I was only 13 at the time...) Much easier to
> calculate it, in my opinion.
>
> Yours looks really good though :)
>
> Bill

I realized it couldn't be torus sections when I was trying to figure out
placement,  Then I realized I couldn't even just shear the sections.  The
next thought was sphere_sweep, but that was a bit of a pain, so I just
ended up using a lot of spheres. (3000 in fact, but I think it could be
less at this resolution.)  That suddenly made the color a lot easier than
if I had used the other methods.

I also tried making colored smoke or neon, but it looks really flat when the
light of the back parts shines through the front parts and the colors merge
together.

Anyone know how to make translucent smoke that is opaque in just the right
parts?  I was thinking of a neon sign without the glass tubing, or perhaps
a white fog tube with a bright colored wire running through the center to
light it.  Maybe it can't be done, or maybe I just haven't figured out what
I'm doing yet.  Any hints?

Jon

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That's really very pretty.

(I like shiney things!)

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"Jon Buller" <jon### [at] bullersnet> wrote in message 
news:web.43c7e1af9d79c9cbe920ef30@news.povray.org...
> Anyone know how to make translucent smoke that is opaque in just the right
> parts?  I was thinking of a neon sign without the glass tubing, or perhaps
> a white fog tube with a bright colored wire running through the center to
> light it.  Maybe it can't be done, or maybe I just haven't figured out 
> what
> I'm doing yet.  Any hints?

Not sure what you're asking. Pov's media will give a good smoke/fog. To get 
a neon effect you'd want a media with emission in the colour of the neon, 
absorption in grey (to provide the opacity, but probably much less than the 
emission value), and then mess with the density to make it look right.

That should be a pretty accurate neon effect, since the gas in neon tubes is 
at constant density, though you may get a nicer effect by using a density 
pattern that follows your shape so you can get a brighter, more dense part 
in the middle. Personally I'd avoid it because it's really hard making 
patterns that accurately follow shapes.

That any help? I can bash together some sample code if you're interested.

BTW, your image seems sort of familiar to me: 
http://evilsuperbrain.com/?bgID=1 :)

-- 
Tek
http://evilsuperbrain.com

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"Tek" <tek### [at] evilsuperbraincom> wrote:
> "Jon Buller" <jon### [at] bullersnet> wrote in message
> news:web.43c7e1af9d79c9cbe920ef30@news.povray.org...
> > Anyone know how to make translucent smoke that is opaque in just the right
> > parts?  I was thinking of a neon sign without the glass tubing, or perhaps
> > a white fog tube with a bright colored wire running through the center to
> > light it.  Maybe it can't be done, or maybe I just haven't figured out
> > what
> > I'm doing yet.  Any hints?
>
> Not sure what you're asking.

The problem is, neither am I.  I have this vague image in my mind, but I
don't think it's consistent enough to actually be tangible.  I just thought
it would look cool if it was foggy and glowed.

> Pov's media will give a good smoke/fog. To get
> a neon effect you'd want a media with emission in the colour of the neon,
> absorption in grey (to provide the opacity, but probably much less than the
> emission value), and then mess with the density to make it look right.

I took an example (I think it was in the portfolio dir) and played with it
a bit...  Got the attached image which I think sucks compared to the mirror
one.  Esp. the parts where it overlaps.  Maybe I just need to play with it a
lot more, but that was bad enough (and made me think about the translucent
"problem" to think that what I was imagining might not be consistent enough
to implement.

> That any help? I can bash together some sample code if you're interested.

Thanks, but don't bother until I figure out what I'm actually trying to
visualize.

> BTW, your image seems sort of familiar to me:
> http://evilsuperbrain.com/?bgID=1 :)

Yes, I made a version like that too, because of that HOF image.  I didn't
think the knot would look quite as close to the linked rings as it does,
until I did it.  I was just thinking of doing the knot like the links,
torus sections tight enough to just be tangent to the other parts of the
object.

The links were a lot harder to make the colors fade into each other
though... 8^)  Maybe I should have used a figure-8 knot instead of the
trefoil, so the plagerism wouldn't be so obvious.

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