On 31/05/2013 2:05 PM, LanuHum wrote:
> Alain, Thanks, but I don't understand your idea
> Each object has own matrix. If I transform one, it will be necessary to
> transform all remaining
> The response is found in Povray documentation: matrix
> Users of Blender prompted that my problem was that axes of coordinates are
> various in Blender and in Povray


Another way of saying what Alain said in non technical terms.

When you set the location of the spotlight (you set it to < 0,0,0 >) 
then set the point_at. PovRay will calculate the angles. If you then 
transpose the spotlight the point_at will still keep these angles and 
the light beam will miss your sphere.

An alternative method would be to take the spotlight coordinates from 
your Blender light and use them as the location in the PovRay Spotlight. 
Then the point_at will work as you want it to if you do not add any more 
translations or rotations.
Be aware if you do this then the centre of rotation of the spotlight 
will be at the origin.

Example:

#declare Sphere_001 =
sphere {
0.0, 0.500000
texture{ Non_Patterned_Texture }
rotate    <0.000000,0.000000,0.000000>
translate <3.000000,1.000000,0.000000>
}

#declare Light_Source1 =
light_source {
< 3.196899, 5.407235, -3.876671 >, colour rgb <0.600,0.600,0.600>
spotlight
point_at < 3.000000, 1.000000, 0.000000 >
radius 32.549
falloff 37.500
tightness 0
fade_power 2.000
fade_distance 14.900
media_attenuation off
media_interaction on
}

-- 
Regards
     Stephen

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