Hi guyz!

Maybe somebody can help me. :) How can I define a
God's Eye coordinate system (or a camera orientation)
in POV?
(a right-handed coordinate system where z points
to upward)

Thanks,
Timothy

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"timothy76" <tim### [at] freemailhu> wrote in message
news:web.3f969ac27f55714aa9f5a3110@news.povray.org...
>
> Maybe somebody can help me. :) How can I define a
> God's Eye coordinate system (or a camera orientation)
> in POV?
> (a right-handed coordinate system where z points
> to upward)

Use keywords 'up' and 'sky' in the camera statement, with +z as their values
or a vector of <0,0,1>, and keyword 'right' as -y or <0,-1,0>.

If you intend to use the 'direction' keyword make sure it is also set to a
+y value or vector; 'angle' doesn't use a vector or axis so that should be
okay as is.

I think this is how to set up the right-handed system in POV-Ray. Hopefully
someone else can confirm this... or just test it out and you will find out
quickly by doing some hand acrobatics.

-- 
Bob H.
http://www.3digitaleyes.com

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timothy76 wrote:
> 
> Hi guyz!
> 
> Maybe somebody can help me. :) How can I define a
> God's Eye coordinate system (or a camera orientation)
> in POV?
> (a right-handed coordinate system where z points
> to upward)


camera {
	sky z
	location pCamLoc
	look_at pCamEye
}

As long as pCamEye-pCamLoc is not parallel to z, you should be fine.

Regards,
John

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In article <3F96CA14.2D83FCA5@hotmail.com>,
 John VanSickle <evi### [at] hotmailcom> wrote:

> camera {
> 	sky z
> 	location pCamLoc
> 	look_at pCamEye
> }
> 
> As long as pCamEye-pCamLoc is not parallel to z, you should be fine.

He wanted a right handed system, so the right and up vectors need to be 
specified as well.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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On Wed, 22 Oct 2003 10:57:06 EDT, "timothy76" <tim### [at] freemailhu>
wrote:

>Hi guyz!
>
>Maybe somebody can help me. :) How can I define a
>God's Eye coordinate system (or a camera orientation)
>in POV?
>(a right-handed coordinate system where z points
>to upward)
>
>Thanks,
>Timothy
>


like this? :

camera {
  location
  direction <0, 0, 1> // y points forward (maybe -1,
                      // depending on what you mean
                      // by right handed)
  up <0, 0, 1>  // z points to upward
  right <(image_width / image_height), 0, 0>
  // or -(image)width / image_height, depending
  // on what you mean by right handed)
  // optional rotate camera here
  // optional translate camera here
}


direction, up, and right define the coordinate
system for the render.  don't use look_at with
them or it might revert to the regular POV
coords

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Thanks for the quick answer! :)
I've checked that this is works well:

camera {
   location ...
   look_at ...
   right <-4/3,0,0>
   sky <0,0,1>
}

Thanks again!
Timothy

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In article <web.3f985bab982f6de9f868cbfe0@news.povray.org>,
 "timothy76" <tim### [at] freemailhu> wrote:

> Thanks for the quick answer! :)
> I've checked that this is works well:
> 
> camera {
>    location ...
>    look_at ...
>    right <-4/3,0,0>

You could also do this:
right <-image_width/image_height, 0, 0>

That way, the image renders with the proper aspect ratio even when you 
change the image dimensions.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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Christopher James Huff wrote:

> You could also do this:
> right <-image_width/image_height, 0, 0>
> 
> That way, the image renders with the proper aspect ratio even when you 
> change the image dimensions.

Let me add this : don't forget the consequences of using a right-hand/z 
up camera on some 'oriented' features, especially :
  - torus
  - layered fog
  - sky sphere
  - image_maps
  - height-fields

Fabien.

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