Thorsten Froehlich wrote:
> 
> In article <380922BD.C98E15DF@isd.net> , Larry Fontaine <lfo### [at] isdnet>
> wrote:
> 
> > If you have a torus with minor>major, you get a big ugly hole chopped
> > out of the center. Shouldn't it just be like a torus without a hole,
> > like a red blood cell sort of thing?
> 
> Yes, I can reproduce your problem, here is a sample scene. It should show a
> strange dark spot near the center of the torus. (Crossposted to POV-Ray
> bugreports.)

Is it really a bug when you try to make a torus something other than a torus ?

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

How is that not a torus? A torus is defined simply as the solid formed by rotating
a circle around a circular path which is perpindicular to the plane of the circle.

Ken wrote:

> Thorsten Froehlich wrote:
> >
> > In article <380922BD.C98E15DF@isd.net> , Larry Fontaine <lfo### [at] isdnet>
> > wrote:
> >
> > > If you have a torus with minor>major, you get a big ugly hole chopped
> > > out of the center. Shouldn't it just be like a torus without a hole,
> > > like a red blood cell sort of thing?
> >
> > Yes, I can reproduce your problem, here is a sample scene. It should show a
> > strange dark spot near the center of the torus. (Crossposted to POV-Ray
> > bugreports.)
>
> Is it really a bug when you try to make a torus something other than a torus ?
>
> --
> Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Larry Fontaine wrote:
> 
> How is that not a torus? A torus is defined simply as the solid formed by rotating
> a circle around a circular path which is perpindicular to the plane of the circle.

Tell me oh bright young one what advantage if any is there in trying
to make the lesser radius larger than the greater radius ?

What do you hope to achieve anyway ?

Why are you bucking the system ?

Where is my other sock ?

Got milk ?

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

> Got milk ?

Or, as the slogan ran when translated (into Spanish I think): "Are you
lactating?"

Post a reply to this message

This problem first came up when modelling my TI-89. At the top-front-left and
top-front-right corners.
Consider this: say you want a rounded prism of a rounded rectangle; ie, a roundbox of
sorts except that the x-parallel, y-parallel, and z-parallel edges are rounded by
different amounts, and we want all rounding to be cylindrical. Let's say the x and z
parallel edges are rounded by 1, and the y parallel edges are rounded by 1.5. At the
corners, rather than spheres, you would need torii. Specifically, torii of major
radius
(1.5-1) and minor radius of 1, ie major < minor. This is what advantage there is, what
I
had hoped to achieve, and why I am bucking the system.

Your other sock is stuck to the top inside the drier. You must not have seen it.

There is both skim and 1% in the refridgerator.

Ken wrote:

> Larry Fontaine wrote:
> >
> > How is that not a torus? A torus is defined simply as the solid formed by rotating
> > a circle around a circular path which is perpindicular to the plane of the circle.
>
> Tell me oh bright young one what advantage if any is there in trying
> to make the lesser radius larger than the greater radius ?
>
> What do you hope to achieve anyway ?
>
> Why are you bucking the system ?
>
> Where is my other sock ?
>
> Got milk ?
>
> --
> Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

In article <380A78B9.C9B4BE1B@pacbell.net> , Ken <tyl### [at] pacbellnet>  
wrote:

> Is it really a bug when you try to make a torus something other than a torus ?

Well, even if it is not, then it is a degenerate torus and a appropriate
warning messages should be issued ;-)   And besides that, fixing it is
rather easy, so just doing so and accepting such torii is no longer a
problem.


   Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message

Tienes leche? Hehehe... actually, you're right, it can be interpreted as Do
YOU have milk? Ah, the imperfections and limitations of language... don'tcha
love 'em?

Post a reply to this message

Thorsten Froehlich wrote:

> > Is it really a bug when you try to make a torus something other than a torus ?
> 
> Well, even if it is not, then it is a degenerate torus and a appropriate
> warning messages should be issued ;-)   And besides that, fixing it is
> rather easy, so just doing so and accepting such torii is no longer a
> problem.
> 
>    Thorsten

Your reply has been accepted.

:)

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

On Sun, 17 Oct 1999 21:28:24 -0500, Larry Fontaine <lfo### [at] isdnet>
wrote:

>How is that not a torus? A torus is defined simply as the solid formed by rotating
>a circle around a circular path which is perpindicular to the plane of the circle.

AFAIR, from the point of view of topology, a torus is defined as the
surface formed by moving a closed curve along a smooth (i.e. with a
definite tangent in every point) and closed path with the plane the
curve lies in always perpendicular to  the tangent of the path. A
circular torus is a special case.


Peter Popov
ICQ: 15002700

Post a reply to this message

Ken <tyl### [at] pacbellnet> wrote:

[snip...]
>
> Is it really a bug when you try to make a torus something other than a
torus ?
>

http://www.treasure-troves.com/math/StandardTori.html

Gerald

Post a reply to this message