Am 22.09.2018 um 07:41 schrieb Mike Horvath:
> Is there a way to change the handedness of a scene? I am doing a lot of
> astronomy calculations, and they are all right handed.

In POV-Ray, handedness is defined by the camera. The defaults

    right     x*1.33
    up        y
    direction z

or, in v3.8.0

    right     x*image_width/image_height
    up        y
    direction z

result in a left-handed coordinate system. For a right-handed coordinate
system, you have to set one (or all three) of these vectors to the
opposite direction, e.g.:

    direction -z


Note that this works even if you override the actual directions by using
`look_at`.


Note that this also has an effect on textures; you may need to mirror
planet image maps (e.g. using `scale <-1,1,1>` in the image map) to get
correct results.


> If not, could such a setting be added to POV-Ray? Thanks.

I intend to add an explicit "handedness" parameter to the global
settings, for more intuitive switching, including a change in the
behaviour of UV mapping and image map projection types. But it'll be a
while until I get around to that.

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