 |
 |
|
 |
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
How can I make an ellipse (cylinderical)?
Thanks for your help.
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
In article <4061d956$1@news.povray.org> , "John" <joh### [at] msn com> wrote:
> How can I make an ellipse (cylinderical)?
You scale a sphere asymetrically. I.e. add "scale <1,10,1>" to a sphere.
Thorsten
____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trf de
Visit POV-Ray on the web: http://mac.povray.org
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
"Thorsten Froehlich" <tho### [at] trf de> wrote in message
news:4061dc5d$1@news.povray.org...
> In article <4061d956$1@news.povray.org> , "John" <joh### [at] msn com>
wrote:
>
> > How can I make an ellipse (cylinderical)?
>
> You scale a sphere asymetrically. I.e. add "scale <1,10,1>" to a sphere.
>
> Thorsten
>
same goes with a cylinder.
cylinder {
<0, 1, 0>,
<0, -1, 0>, 1
scale <3, 1, 1>
//... and so on
}
or if you want a thin flat one, a disc object could be scaled.
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
Thorsten Froehlich <tho### [at] trf de> wrote:
> > How can I make an ellipse (cylinderical)?
> You scale a sphere asymetrically. I.e. add "scale <1,10,1>" to a sphere.
Actually that's an ellipsoid.
(Colloquially, that is. I wouldn't bet my money on whether a
mathematician would agree...)
--
plane{-x+y,-1pigment{bozo color_map{[0rgb x][1rgb x+y]}turbulence 1}}
sphere{0,2pigment{rgbt 1}interior{media{emission 1density{spherical
density_map{[0rgb 0][.5rgb<1,.5>][1rgb 1]}turbulence.9}}}scale
<1,1,3>hollow}text{ttf"timrom""Warp".1,0translate<-1,-.1,2>}// - Warp -
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
Warp wrote:..
> Thorsten Froehlich <tho### [at] trf de> wrote:
> > > How can I make an ellipse (cylinderical)?
>
> > You scale a sphere asymetrically. I.e. add "scale <1,10,1>" to a sphere.
>
> Actually that's an ellipsoid.
> (Colloquially, that is. I wouldn't bet my money on whether a
> mathematician would agree...)
>
>
Of course that's an ellipsoid.
An ellipse is a curve. One can find many examples to represent a curve
using povray. Best of all is starting with a parametrical representation
for the curve. x = a*cos(t), z=b*sin(t), y=0 (0<=t<=2*pi) represents an
ellipse in the (XZ)-plane with axes 2a and 2b.
One method to represent curves using povray consists in constructing
small cylinders, an other method in constructing small spheres in
neighbouring points.
--
home page: http://cage.ugent.be/~hs
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
HermanS <sas### [at] pandora be invalid> wrote:
> Of course that's an ellipsoid.
> An ellipse is a curve. One can find many examples to represent a curve
> using povray. Best of all is starting with a parametrical representation
> for the curve. x = a*cos(t), z=b*sin(t), y=0 (0<=t<=2*pi) represents an
> ellipse in the (XZ)-plane with axes 2a and 2b.
I know that an ellipse is a curve and its mathematical representation.
However, what I said is that I wouldn't bet my money on claiming that
an unevenly scaled sphere is a mathematically correct ellipsoid (at least
not without trying to get the mathematical relation between the two).
It's an ellipsoid in the colloquial sense of "elongated sphere", but
is it an ellipsoid as defined mathematically is another question. :)
--
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
Can we use this "scale" with torus?
"Thorsten Froehlich" <tho### [at] trf de> wrote in message
news:4061dc5d$1@news.povray.org...
> In article <4061d956$1@news.povray.org> , "John" <joh### [at] msn com>
wrote:
>
> > How can I make an ellipse (cylinderical)?
>
> You scale a sphere asymetrically. I.e. add "scale <1,10,1>" to a sphere.
>
> Thorsten
>
> ____________________________________________________
> Thorsten Froehlich, Duisburg, Germany
> e-mail: tho### [at] trf de
>
> Visit POV-Ray on the web: http://mac.povray.org
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
"John" <joh### [at] msn com> wrote in message news:40630650$1@news.povray.org...
> Can we use this "scale" with torus?
You can use any scale you like with a torus - just remember to charge them torus
rates...
Sorry. Yes. You can.
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |
|  |
|
 |
In article <4062e844@news.povray.org>, Warp <war### [at] tag povray org>
wrote:
> It's an ellipsoid in the colloquial sense of "elongated sphere", but
> is it an ellipsoid as defined mathematically is another question. :)
A sphere is technically an ellipsoid. All shapes formed by uneven
scaling of spheres are ellipsoids, and are described by the equation:
x^2/a^2 + y^2/b^2 + z^2/c^2 = 1
Anyway, a "cylinderical ellipse" doesn't make sense, but the
"cylinderical" part is making me think of an elliptic cylinder:
http://mathworld.wolfram.com/EllipticCylinder.html
x^2/a^2 + y^2/b^2 = 1
--
Christopher James Huff <cja### [at] earthlink net>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tag povray org>
http://tag.povray.org/
Post a reply to this message
|
 |
|  |
|  |
|
 |
|
 |
|  |