MR wrote:
> 
> hello,
> 
> how does a rotation vector work?  i have no problem with
> a simple degree rotation around an axis, such as:
> 
> box { <0,0,0>, <1,1,1> rotate y*180}
> 
> thats a half-circle rotation around the y axis... but what is
> this:
> 
> box { <0,0,0>,<1,1,1> rotate <0,1,0> }
> 
> i tried various values, and i couldn't get a good feel for what
> it does... it doesn't appear to be a simple rotation around
> the y axis in radians....  i substituted pi for the 1 and didn't
> get a 180 degree rotation.
> 
> thanks, miker

Rotate y*180 is simply short hand for rotate <0,180,0>. The rotations are taken
by order of xyz so if you specified rotate < 90, -45, 0> then pov would evaluate
this as rotate first +90 degrees around x-axis then -45 degrees around the y-axis.
You can also multiply rotation vectors like: rotate <0,90,0>*2 is equivelant to
rotate y*180. If you rotate by PI by the way you are simply rotating 3.1415
degrees and it would be hardly visible :)

-- 
Ken Tyler
  
mailto://tylereng@pacbell.net
http://home.pacbell.net/tylereng/links.htm

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