any one know why when i have a set of planes like the diagram below i
can't use fog it says camera in non hollow object "o" is the campera
looking at the smi transpetant planes
               yyy
                | | |
o               | | |
_______  | | |_____z
________| | |_____z
________| | |_____z

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It might be because your planes are pointing the wrong way. One side of
the plane might be considered the inside.


Nobot wrote:

> any one know why when i have a set of planes like the diagram below i
> can't use fog it says camera in non hollow object "o" is the campera
> looking at the smi transpetant planes
>                yyy
>                 | | |
> o               | | |
> _______  | | |_____z
> ________| | |_____z
> ________| | |_____z

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Planes are solid objects. They are as solid as a sphere or a box.
The plane divides the world into to parts: one side is outside and the
other side is inside. A plane is like a floor. You can stand on the floor,
ie. you are outside the floor, or you can dig a hole in the floor and go
inside it.
  The normal vector of the plane points _outside_ the plane. This means that
the direction of the normal vector is significant.
  It the normal vector of the plane points towards the camera, then the
camera will be outside the plane. If the normal vector points away from
the camera, then the camera will be inside the plane.
  It's as simple as that.


  PS. I have always wondered, why many people is confused with planes.
I understood the solidness of planes since the very first time I read
about them in the pov documentation. I have never got confused about
it.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Nieminen Mika wrote:

>   PS. I have always wondered, why many people is confused with planes.
> I understood the solidness of planes since the very first time I read
> about them in the pov documentation. I have never got confused about
> it.

 I think a lot of people think of a plane object as an object similar to
a piece of paper with no deminsions in two directions but a finite
thickness. It is this misconception that causes the confusion.


-- 
Ken Tyler

mailto://tylereng@pacbell.net

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Ken <tyl### [at] pacbellnet> wrote:
:  I think a lot of people think of a plane object as an object similar to
: a piece of paper with no deminsions in two directions but a finite
: thickness. It is this misconception that causes the confusion.

  Perhaps "plane" should be changed to "infinite_box".

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Somehow, "Reflective sphere over checkered infinite_box" doesn't quite have
the same ring to it.. *grin*

Nieminen Mika wrote:

>   Perhaps "plane" should be changed to "infinite_box".

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Alex Vandiver wrote:
> 
> Somehow, "Reflective sphere over checkered infinite_box" doesn't quite have
> the same ring to it.. *grin*

 I agree that certain eshetics must be maintained and this is one of them.
Besides "plane" is much easier to type than Warp's alternative identifier.


-- 
Ken Tyler

mailto://tylereng@pacbell.net

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Nieminen Mika wrote:
> 
> Ken <tyl### [at] pacbellnet> wrote:
> :  I think a lot of people think of a plane object as an object similar to
> : a piece of paper with no deminsions in two directions but a finite
> : thickness. It is this misconception that causes the confusion.
> 
>   Perhaps "plane" should be changed to "infinite_box".

maybe "half-space"? BTW, would a very big box render faster than a plane
or vice versa?

Just curious,
/PETER/

-- 
Peter Santo (PUMP development)
Visit: http://www.ieee.rwth-aachen.de/mp3/

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Peter Santo <san### [at] poolinformatikrwth-aachende> wrote:
: maybe "half-space"? BTW, would a very big box render faster than a plane
: or vice versa?

  I have always noticed, that planes are strangely slow to render, while
boxes are much faster, and I have always wondered why. In a box, you have to
test the intersection with 8 sides while in a plane you have to test the
intersection with just one side. If you make 50 big boxes it surely will
render faster than 50 planes.
  Can anyone explain why is this?

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Maybe because planes are bounded larger?   I never really compared them, but
that's my guess.

-Mike

Nieminen Mika wrote:

> Peter Santo <san### [at] poolinformatikrwth-aachende> wrote:
> : maybe "half-space"? BTW, would a very big box render faster than a plane
> : or vice versa?
>
>   I have always noticed, that planes are strangely slow to render, while
> boxes are much faster, and I have always wondered why. In a box, you have to
> test the intersection with 8 sides while in a plane you have to test the
> intersection with just one side. If you make 50 big boxes it surely will
> render faster than 50 planes.
>   Can anyone explain why is this?
>
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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