I am trying to determine 
the vectors for an area light give that I have two 
and from points and a desired width and height for 
the area light.

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"Danni Coy" <rgc### [at] midcoastcomau> wrote in message
news:pan### [at] midcoastcomau...
> I am trying to determine
> the vectors for an area light give that I have two
> and from points and a desired width and height for
> the area light.

I'm not sure I understand what you are asking for, but have you checked out the
"orient" keyword for area lights?

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> 
> I'm not sure I understand what you are asking for, but have you checked out the
> "orient" keyword for area lights?

I am writing a plugin and I am not certain of how to
use the two vector statements in the area light setup. 
I need to generate these after the user has specified the
to and from points of the light and the height and width of
the area plane.

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Danni Coy <rgc### [at] midcoastcomau> wrote:
> I am writing a plugin and I am not certain of how to
> use the two vector statements in the area light setup. 
> I need to generate these after the user has specified the
> to and from points of the light and the height and width of
> the area plane.

  You can create the area light at the origin, use the Point_At_Trans()
macro to reorient it so that it heads to the correct direction and then
translate it to its place.
  It could look like this:

light_source
{ 0, COLOR
  area_light x*WIDTH, z*HEIGHT, ACCURACY, ACCURACY
  adaptive ADAPTIVENESS
  Point_At_Trans(TO-FROM)
  translate FROM
}

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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