news:web.447b0af0f93ecc724de801770@news.povray.org...
> Oh... it looks great to me too..... all I mean is... why did "hollow on"
> work so well?  And why did "hollow off" cut away the atmosphere?  Just
> trying to learn POV-Ray...
>
Well as said said Tim, POV discs are like POV planes. They are both a
surface without thickness  and a half-space i.e. it cuts the whole POV
universe in 2 halves : outside and inside
"The inside of a disc is the inside of the plane that contains the disc.
Also note that it is not constrained by the radius of the disc." (doc
3.4.2.2).
in fact it seems that a disc is a plane which surrounding and hole are
transparent .
 Now the inside of an object may perform media only if it is declared as
hollow.

Why does a plane have an inside as many other POV primitives? It is useful
when you want to make a sea with an interior (fade_color, media etc..) or in
CSG to cut an object by difference or intersection.

Marc

Post a reply to this message

"M_a_r_c" <jac### [at] wanadoofr> wrote:

> news:web.447b0af0f93ecc724de801770@news.povray.org...
> > Oh... it looks great to me too..... all I mean is... why did "hollow on"
> > work so well?  And why did "hollow off" cut away the atmosphere?  Just
> > trying to learn POV-Ray...
> >
> Well as said said Tim, POV discs are like POV planes. They are both a
> surface without thickness  and a half-space i.e. it cuts the whole POV
> universe in 2 halves : outside and inside
> "The inside of a disc is the inside of the plane that contains the disc.
> Also note that it is not constrained by the radius of the disc." (doc
> 3.4.2.2).
> in fact it seems that a disc is a plane which surrounding and hole are
> transparent .
>  Now the inside of an object may perform media only if it is declared as
> hollow.
>
> Why does a plane have an inside as many other POV primitives? It is useful
> when you want to make a sea with an interior (fade_color, media etc..) or in
> CSG to cut an object by difference or intersection.
>
> Marc

OoOOoOoohh!!! OUTSIDE and INSIDE.... ok thanks for explaining this Marc, and
thank you Tim for providing the clue about "hollow on" for discs.

For a special treat, I'll re-render my ringed planets and post them over a
few weeks... (I'm giving myself a few weeks because I have a busy
schedule...)

Post a reply to this message

EagleSun wrote:

 > OoOOoOoohh!!! OUTSIDE and INSIDE.... ok thanks for explaining this
 > Marc, and thank you Tim for providing the clue about "hollow on" for
 > discs.

Hey, no problem. Glad to be of use. :-)

Regards,
Tim

-- 
aka "Tim Nikias"
Homepage: <http://www.nolights.de>

Post a reply to this message