POV-Ray : Newsgroups : povray.newusers : unexpected result with orthographic camera : unexpected result with orthographic camera Server Time
5 Sep 2024 08:20:44 EDT (-0400)
  unexpected result with orthographic camera  
From: Dawn McKnight
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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