POV-Ray : Newsgroups : povray.advanced-users : look_at for objects? : Re: look_at for objects? Server Time
30 Jul 2024 10:17:56 EDT (-0400)
  Re: look_at for objects?  
From: Josh English
Date: 17 Mar 2000 15:01:00
Message: <38D28FE6.11C7C0FF@spiritone.com>
#macro Orient_Z(v1,v2)
  #local nx = vnormalize(v2-v1);
  #local nz = vnormalize(vcross(nx,y)); // replace "y" with the things local
"up"
  #local ny = vcross(nz,nx)
  matrix <nx.x, nx.y, nx.z,
              ny.x, ny.y, ny.z,
              nz.x, nz.y, nz.z,
              v1.x, v1.y, v1.z>
#end

This takes an object at the origin and places it at point v1 and points it
towards v2.
It is based on John Vansickles Reorient macro. I havne't figured out how to
do autobanking

Josh

Andrew Clinton wrote:

> Hello,
>
> Is there any macro available that will perform on an object the same
> function as the look_at command does in a camera?
>
> In other words, I have an object at <0,0,0> and oriented in the +z
> direction, and I wish to perform an x-rotation then a y-rotation so that
> the object is now pointing at a given point (as in the look_at point for
> the Camera).  I've been using John VanSickle's Reorient macro, but in
> some cases the object receives an undesireable z-rotation so that it
> becomes tilted wrong.
>
> I've been banging my head for a while about this, any help would be
> appreciated!
>
> Andrew C

--
Josh English
eng### [at] spiritonecom
"May your hopes, dreams, and plans not be destroyed by a few zeros."


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