POV-Ray : Newsgroups : povray.binaries.images : vrotate example from p.general : Re: vrotate example from p.general Server Time
29 Jul 2024 22:28:45 EDT (-0400)
  Re: vrotate example from p.general  
From: Bald Eagle
Date: 18 Aug 2013 22:45:00
Message: <web.521185a0286ea7962c424ebe0@news.povray.org>
> Note that <0,0,0> has no direction, so the angle between it and any
> other given vector is poorly defined. The function has to return
> /something/, and it decides to return 90 because it's just as good or
> bad as any other answer in that situation.

Except now we're being all loosey-goosey with the definition of "vector".
I would have understood or _assumed_ that like everything else, these would be
location vectors, not direction vectors.

Considering that VDist(A,B) gives me the distance between two location vectors,
I would be tempted to assume that if I wanted to draw a line between said points
(in the plane {z, 0}, I would draw a line from the origin to <VDist(A,B), 0, 0>,
and then rotate it by VAngleD(A,B), then translate it by <A.x, A.y, 0>

So yes, once again the directive does exactly what the documentation says it
does, but the documentation is not clear WHICH definition of "vector" is being
applied when interpreting the directive.

Now, granted, I do stoopid things and confuse myself all the time, but this was
a tricksy one, oh yes my preciousssss.  Very tricksy indeed.  Nasty little
directiveses.  Not like End User it does.  Hates us.

But it's ok, I'll be fine.  The nice doctors said everything's gonna be "just
fine."  :D


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