POV-Ray : Newsgroups : povray.documentation.inbuilt : Orientation and left handed frame : Re: Orientation and left handed frame Server Time
16 Jan 2022 18:02:31 EST (-0500)
  Re: Orientation and left handed frame  
From: lelama
Date: 4 Oct 2016 12:10:01
Message: <web.57f3d431844df07321263ef70@news.povray.org>
> >
> > These two choices may be done independently. The documentation suggests that
> > these two choices are dependent, making the doc difficult to read.
>
> I don't see the documentation implying anything of that sort. It simply
> describes how POV-Ray does things, and neither asserts nor denies a
> connection between the two features.
>

The doc says that povray is a left handed system and uses the left hand for both
the axis relative locations and the rotations. It was not clear to me when I
read the doc whether I can change the default behaviour and use the left hand
for the axis and the right hand for the roations.

The default choices are clearly documented. But, what if we change the default
convention ?  I see no place in the doc where it is written if we can make the
choices for the axis and for the rotations independently.

As far as I understand, this is not possible to choose the conventions
independently (whereas it is logically possible in principle). I think it would
be more clear if it was written explicitly that it is not possible.


> - What /is/ the "left handed convention"? The current wording easily
> explains POV-Ray's coordinate system by means of physiological
> properties shared by well over 99.99% of all human beings, rather than
> relying on the reader being familiar with arbitrary conventions
> established in mathematics or computer graphics.

Yes, OK with that.  My problem is not with the wording. It is about the fact
that ( if I am correct ) only two conventions are possible among the 4 possible
choices that exist in theory.

Laurent.


Post a reply to this message

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.