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14 Nov 2024 06:15:02 EST (-0500)
  An Object outside the skysphere (Message 1 to 6 of 6)  
From: Handler
Subject: An Object outside the skysphere
Date: 28 Mar 1999 10:29:15
Message: <36FE4B0C.33B34ED5@taconic.net>
I was just playing around with the skyphere, trying to make a space like
scene.  Now I want to put a planet(s) outside the "world."  And have no
idea where to look for it.  I'd be glad for the little bit of a push to
get me going.

Attached is the .pov file that I am working on.


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Attachments:
Download 'space.pov.txt' (4 KB)

From: Ken
Subject: Re: An Object outside the skysphere
Date: 28 Mar 1999 10:45:11
Message: <36FE4D70.21CFF646@pacbell.net>
Handler wrote:
> 
> I was just playing around with the skyphere, trying to make a space like
> scene.  Now I want to put a planet(s) outside the "world."  And have no
> idea where to look for it.  I'd be glad for the little bit of a push to
> get me going.
> 
> Attached is the .pov file that I am working on.


 The skysphere is actually a virtual object with no real size. You can
not place an object outside of it because it has no limit in size.
Think of the skysphere, fog, and the background feature as white paper
space that your scene is drawn on. It occupies all of the space that
is not physically covered by an object. It is everywhere something else
isn't.
 To get around this you will need to use a sphere object with a large
scale then place your outside planets outside the diameter of the sphere
object. Personally I find using a sphere instead of the skysphere for
my skies gives me more versatility anyway. One advantage to using a 
sphere is that you can scale it unevenly unlike the skysphere which
gives you the added advantage of being able to have flatter cloudscapes
and adjustable horizons.

 I did not look at your file because I don't think it would help in
this case if I did.


-- 
Ken Tyler

mailto://tylereng@pacbell.net


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From: Diane Duane
Subject: Re: An Object outside the skysphere
Date: 1 Jun 1999 15:04:42
Message: <37542092.988CDA9C@iol.ie>
Ken wrote:

>  The skysphere is actually a virtual object with no real size. You can
> not place an object outside of it because it has no limit in size.
> Think of the skysphere, fog, and the background feature as white paper
> space that your scene is drawn on. It occupies all of the space that
> is not physically covered by an object. It is everywhere something else
> isn't.
>  To get around this you will need to use a sphere object with a large
> scale then place your outside planets outside the diameter of the sphere
> object....

This leads into something I was going to inquire about.  If you set up a
"substitute skysphere" like this, is it possible to image_map a .gif
file onto the inside of it?  (Just once.  I want this particular image
to appear in b.g. of the scene.)

Best!  Diane


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From: Bob Hughes
Subject: Re: An Object outside the skysphere
Date: 1 Jun 1999 21:20:28
Message: <375478B1.23F951B9@aol.com>
Sure. And using gif would also allow for clear places too, if so desired.
The 'once' keyword has no effect on map_type 1 (spherical), it is always
once. You may have to place your image into a much larger image having a
blank background and make it's palette index transmit 1. You will need to
use a color not in your image of course. Then just rotate and scale the
sphere until you have it in the background of your scene correctly. This
will also require the spheres center to be where the camera is to not have
disortion.
Put a scale -x in the pigment statement contaning the image_map too so it
will be mirrored correctly.


Diane Duane wrote:
> 
> This leads into something I was going to inquire about.  If you set up a
> "substitute skysphere" like this, is it possible to image_map a .gif
> file onto the inside of it?  (Just once.  I want this particular image
> to appear in b.g. of the scene.)
> 

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto://inversez@aol.com?Subject=PoV-News


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From: Ron Parker
Subject: Re: An Object outside the skysphere
Date: 2 Jun 1999 10:04:45
Message: <37552bed.0@news.povray.org>
On Tue, 01 Jun 1999 19:20:01 -0500, Bob Hughes wrote:
>Sure. And using gif would also allow for clear places too, if so desired.

You can also use png with an alpha channel to get transparent and semi-
transparent parts, independent of color, if you have a program capable 
of creating one.


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From: Bob Hughes
Subject: Re: An Object outside the skysphere
Date: 2 Jun 1999 22:25:07
Message: <3755D959.C995F584@aol.com>
Yep, and I for one am getting to where I can use the Alpha Channel
somewhat. I've run into a few problems though like occasional program
crashes and oddities like totally black areas being unused (or turned to
full transparency) or changes in non-transparent parts of the image when
reused as a image_map. A lot may have to do with my misuse of it so far,
but what does work right about it plainly shows its capabilites.


Ron Parker wrote:
> 
> On Tue, 01 Jun 1999 19:20:01 -0500, Bob Hughes wrote:
> >Sure. And using gif would also allow for clear places too, if so desired.
> 
> You can also use png with an alpha channel to get transparent and semi-
> transparent parts, independent of color, if you have a program capable
> of creating one.

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto://inversez@aol.com?Subject=PoV-News


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