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Yes, I thought it was something like that, but I believe one
can also call a 3D helix shape a spiral. Since pov uses
spirals as 2D textures (and hasn't heard from a helix in
it's entire life), maybe I'm wrong.
> Maybe I'm wrong, but this is what I have understood:
> AFAIK: A spiral is a line on a 2D plane which can be
drawn this way:
>start drawing a circle but increase the radius constantly.
When you have
>made a complete 360 degrees curve, you are a little bit
farther away from
>the center. Continue drawing and you get a spiral curve.
> A helix is a 3D line instead of 2D like the spiral. You
can draw it this
>way: start drawing a circle in the xy-plane, but instead of
changing the
>radius, keep it constant, but increase the z-coordinate,
ie. the height.
>When you have done a complete 360 degrees curve, you are
still at the same
>distance from the center axis, but a little bit higher from
the plane.
>Continue this way and you get a helix curve.
> A galaxy has typically a spiral shape, while a spring has
a helix shape.
>
>--
>main(i){char*_="BdsyFBThhHFBThhHFRz]NFTITQF|DJIFHQhhF";whil
e(i=
>*_++)for(;i>1;printf("%s",i-70?i&1?"[]":"
":(i=0,"\n")),i/=2);} /*- Warp. -*/
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Darcy Johnston wrote:
>
> Does anyone know how to make a true spiral texture, like that of a candy
> cane. I know you can use grandient x+y to simulate one but that only works
> if you have the proper angle. I want to be able to animate it so I need it
> to really spiral up the object.
>
> Any help would be appreciated,
> Thanks,
> Darcy
Since everyone else has suggested the spiral pigment
modifier I thought I would confuse the works now by
suggesting you also take a lood at the radial pigment
modifier.
Ken Tyler
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Speaking of a Helix, where is a program (that exports to different formats)
that makes DNA type Helixes.
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Bloomquist Family wrote:
>
> Speaking of a Helix, where is a program (that exports to different formats)
> that makes DNA type Helixes.
Spiralizer makes some interesting shapes
It might do helixes but I don't remember.
It does do shell shapes, spirals and
has a couple of other useful functions.
It can be downloaded for free at:
http://www.armanisoft.ch/
If you go there also look at their Elephont
text utility. Good stuff !
There is another program I believe called Helixer
but I don't have the URL bookmarked. I think it's
a Mac utility which would explain why it's not been
bookmarked.
There is also an old dos command line utility named
Helix I have on CD I could send you if your interested.
It's fairly simple but it does as the name suggests.
Ken Tyler
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Not really. You've got the spiral bit right, but a spiral doesn't have to
be 2D, it can be a helical spiral (increasing in height, constant radius).
A helix is really the path made by the end point of an unwrapping 2D shape.
Take a square for instance. Pick the bottom right corner and swing it out
to 180 degrees with the left side, now swing this whole line out to 180
degrees to the top side and continue. This will create a 2D path of the end
point of the unwrapping 2D shape, in the case of a square, it will look like
the side view of a sea shell. At least that's what I was taught in graphics
class last month! I think however that by the dictonary term you're right,
it says "A spiral of coil, such as a corkscrew". Strange however that it
would use the word spiral in that description, because by the description of
a spiral and judging on the description it gave of a helix, a helix is
really a special type of spiral... Spiral "(1) A continuous curve moving
around a fixed point at a steadily increasing or decreasing distance, as a
watch-spring. (2) A continuous curve winding round a central axis but
continually changing plane, as in a spiral staircase of the thread of a
screw."
So basically, a helix is a type of spiral. But I'm open to other
interpretations. I think what this all comes down to however is that the
original question in the thread was answered by "spiral1". This produces
the effect needed.
--
Lance.
---
For the latest MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone
Nieminen Mika wrote in message <3674ea52.0@news.povray.org>...
>Julius Klatte <jku### [at] hotmail com> wrote:
>: I understand what the difference between spiral and helix is
>: for POV, but I was just wondering what (as a language thing)
>: the difference between a "spiral" and a "helix" is. I always
>: thought they meant the same thing.
>
> Maybe I'm wrong, but this is what I have understood:
> AFAIK: A spiral is a line on a 2D plane which can be drawn this way:
>start drawing a circle but increase the radius constantly. When you have
>made a complete 360 degrees curve, you are a little bit farther away from
>the center. Continue drawing and you get a spiral curve.
> A helix is a 3D line instead of 2D like the spiral. You can draw it this
>way: start drawing a circle in the xy-plane, but instead of changing the
>radius, keep it constant, but increase the z-coordinate, ie. the height.
>When you have done a complete 360 degrees curve, you are still at the same
>distance from the center axis, but a little bit higher from the plane.
>Continue this way and you get a helix curve.
> A galaxy has typically a spiral shape, while a spring has a helix shape.
>
>--
>main(i){char*_="BdsyFBThhHFBThhHFRz]NFTITQF|DJIFHQhhF";while(i=
>*_++)for(;i>1;printf("%s",i-70?i&1?"[]":" ":(i=0,"\n")),i/=2);} /*-
Warp. -*/
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Ken wrote:
> There is another program I believe called Helixer
> but I don't have the URL bookmarked. I think it's
> a Mac utility which would explain why it's not been
> bookmarked.
Correction:
Helixer is not a Mac utility and will run under
Windows. I forgot it was installed on my system
and found the address for you. Look to:
http://www.evolve.co.uk/helixir/
Sorry for the misinformation contained in my last response.
Ken Tyler
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Julius Klatte wrote:
> > Are you talking about a spiral shape or a helix shape?
>
> I understand what the difference between spiral and helix is
> for POV, but I was just wondering what (as a language thing)
> the difference between a "spiral" and a "helix" is. I always
> thought they meant the same thing.
>
> Julius
The first thought that comes is :
-o- a sipral is a figure in a plane where the radius keeps growing as
you change the angle.
-o- a helix is a figure in 3-d space where the radius is constant but
the height changes as you change the angle.
As it is the way I always used these in physics or biology.
But when looking up the dictionnary (British - Collins Cobuild) you
notice the spiral is actually both these meanings as well as other
figurative meanings, and you discover that the word helix is simply
not there !
Cherio,
Al.
--
ANTI SPAM / ANTI ARROSAGE COMMERCIAL :
To answer me, please take out the Z from my address.
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Helix is in mine (as I mentioned in an earlier post). But a helix by CAD
and graphics terms is not 3D. I can't remember the word for it, perhaps
someone else knows. What is the word for the point that draws a path?
There is a special term for this, and a helix in the 2D sense is one of
these, where the point is the end of the perimeter of an unwinding 2D shape.
But, once again, a helix can be 3D.
--
Lance.
---
For the latest MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone
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Lance Birch wrote:
> Helix is in mine (as I mentioned in an earlier post). But a helix by CAD
> and graphics terms is not 3D. I can't remember the word for it, perhaps
> someone else knows. What is the word for the point that draws a path?
> There is a special term for this, and a helix in the 2D sense is one of
> these, where the point is the end of the perimeter of an unwinding 2D shape.
> But, once again, a helix can be 3D.
If I understand the concept right, in 2D it would only produce a circle, thus of
little interest to the 2D world, that would be what one would call a degenerated
helix (mathematical expression, no bad thoughs there).
In 3D it makes , well a helix ...
Again, if I'm not mistaken, I think you call generally these type of functions
developpants, but a helix would be one case of them. But my maths are a thing of
the past, so there are not too reliable.
Cheers,
Al.
--
ANTI SPAM / ANTI ARROSAGE COMMERCIAL :
To answer me, please take out the Z from my address.
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