POV-Ray : Newsgroups : povray.newusers : unexpected result with orthographic camera Server Time
13 Nov 2024 03:45:41 EST (-0500)
  unexpected result with orthographic camera (Message 1 to 3 of 3)  
From: Dawn McKnight
Subject: unexpected result with orthographic camera
Date: 22 Apr 2001 15:20:24
Message: <3AE32EF6.6D04FD9C@coyotesdaughter.com>
Hi, gang.

I'm still working on my blob fighter.  In order to generate my four-view
sheets, I've taken to using the orthographic camera, instead of the
default.  I've noticed that the top view does something odd.  (See
pictures in p.b.images for reference).

My object lies mostly along the Z axis, with the aft end in +z, and the
bow in -z land.

I set the camera up as follows:

camera {
 orthographic
 location <0, 8, 0>
 right ((4/3)*8)*z
 up 8*x
 look_at <0, 0, 0>
 }

This yields, to my surprise, an image with the prow on the right, not
the left.  This seems odd to me, because, unless I misunderstand how the
right parameter works, I should be saying that the +z side should be on
the right?

Anyway, that's not all that disturbing.  What is disturbing is that I do
some unit markings (decals) with a CSG difference.  When I use the
orthographic camera, as detailed above, the markings become
mirror-imaged.

When I use the default camera, as follows:

camera {
 location <0, 8, 0>
 rotate 90*y
 look_at <0, 0, 0>
 }

I still get the ship in the prow-to-the-right position (planned), and
the decals are left-to-right as read from outboard.

Why does this happen?  Is it a bug, or user error?  What (if anything)
can I do about it?


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From: Bob H 
Subject: Re: unexpected result with orthographic camera
Date: 22 Apr 2001 16:44:25
Message: <3ae342a9@news.povray.org>
Try putting sky <1,0,0> into the camera so that it isn't confused as to what
"up" is.
You might also need to move orthographic after the sky right and up.

Bob H.

"Dawn McKnight" <daw### [at] coyotesdaughtercom> wrote in message
news:3AE32EF6.6D04FD9C@coyotesdaughter.com...
>
> My object lies mostly along the Z axis, with the aft end in +z, and the
> bow in -z land.
>
> camera {
>  orthographic
>  location <0, 8, 0>
>  right ((4/3)*8)*z
>  up 8*x
>  look_at <0, 0, 0>
>  }
>
> This yields, to my surprise, an image with the prow on the right, not
> the left.  This seems odd to me, because, unless I misunderstand how the
> right parameter works, I should be saying that the +z side should be on
> the right?
>
> Anyway, that's not all that disturbing.  What is disturbing is that I do
> some unit markings (decals) with a CSG difference.  When I use the
> orthographic camera, as detailed above, the markings become
> mirror-imaged.
>
> When I use the default camera, as follows:
>
> camera {
>  location <0, 8, 0>
>  rotate 90*y
>  look_at <0, 0, 0>
>  }
>
> I still get the ship in the prow-to-the-right position (planned), and
> the decals are left-to-right as read from outboard.
>
> Why does this happen?  Is it a bug, or user error?  What (if anything)
> can I do about it?


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From: Rick [Kitty5]
Subject: Re: unexpected result with orthographic camera
Date: 22 Apr 2001 21:39:32
Message: <3ae387d4@news.povray.org>
Your also missing the phong highlights...


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Rick

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