POV-Ray : Newsgroups : povray.bugreports : sphere slicing problem : Re: sphere slicing problem Server Time
6 Oct 2022 03:42:59 EDT (-0400)
  Re: sphere slicing problem  
From: Bald Eagle
Date: 18 Oct 2019 16:30:01
Message: <web.5daa1fc0401c58094eec112d0@news.povray.org>
"jr" <cre### [at] gmailcom> wrote:

adding it seems to make no discernable difference to what I now get.

I don't think he was suggesting it would - he was just commenting on my "ex post
facto" differencing comment.  That's a whole different story.

> however, _the_ problem is the "pathological" case of parallel-to-camera, as Bill
> P identified when he asked "what happens with a box".  I'm currently wondering
> whether using a perspective camera for "difficult" shapes mightn't be better.
> and for shapes like spheres + tori I may get milage our of lowering the vertical
> resolution (ie thicker slices).

This almost makes me wonder if you can do some sort of weird wide-angle /
panoramic render and then re-map it with --- for lack of a better understanding
and proper vocabulary - an anamorphic camera

> the Lohmueller tip is confusing.  haven't tried yet but the documentation is
> quite clear that the direction vector is not used with prthographic cameras.
> have you come across working code which utilises the "trick"?

I believe you can just make a simple animation of a camera getting closer and
closer to a shape with a gradient pigment along the object-camera axis.  Maybe
slightly off-axis, so that you can see the effect better.

The camera will start to exclude all of the parts of the object "behind" it, and
you'll effectively get a slicing effect.
I've done this plenty of times by accident when setting up scenes with the
orthographic camera.

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