/*
Hi All,

while trying to track down a reported bug in Moray, I have either
found a bug in POV-Ray 3.1g or there is something I don't
understand<g>.

The following is a simplified scene from Moray (I've converted the
camera to LH coords) that demonstrates the problem. I make a union of
a sphere and a light and copy that around. It seems to me that the
lights are being placed at the incorrect position.

Is this a bug or is my reasoning incorrect in thinking that the lights
should be placed where the LightHolder object should be and that all
the big spheres should be illuminated directly from above (the left)?

Thanks,

- Lutz
*/

default { texture { pigment { rgb <1,0,0> } } }

background { color <0.000,0.000,0.000> }

camera {
  location  <    -50.000,     0.0,      25.000>
  look_at   <     0.00,       0.0,       0.0>
  angle 30
}

// Declare a light source
#declare Light001 = light_source {
  <0.0, 0.0, 0.0>
  color rgb <1.000, 1.000, 1.000>*0.3
  translate  <0 , 0, 1.5>
}

// Declare a sphere at the same position
#declare LightHolder = sphere {
  <0.0, 0.0, 0.0>, 1
    no_shadow
    scale 0.3
    translate  <0, 0, 1.5>
}

// Declare a union that contains both the light and the sphere as well
as another sphere
#declare Group001 = union {
  object { Light001 }
  object { LightHolder }
  
  sphere { // a sphere to be illuminated
    <0,0,0>,1
  }
  // Translate it out along X so that we can orbit the copies
  translate  <10.0, 0.0, 0.0>
}

object {  Group001                 }
object {  Group001 rotate 45.0*z   }
object {  Group001 rotate 90.0*z   }
object {  Group001 rotate 135.0*z  }
object {  Group001 rotate 180.0*z  }
object {  Group001 rotate 225.0*z  }
object {  Group001 rotate 270.0*z  }
object {  Group001 rotate 315.0*z  }



- Lutz
  email : lut### [at] stmuccom
  Web   : http://www.stmuc.com/moray

Post a reply to this message

They are in the right place, just everything is getting illuminated by all the
lights together which throws off your perception.  Check with the following used
in place for the light sources instead:

// Declare a light source
#declare Light001 = light_source {
  <0.0, 0.0, 0.0>
  color rgb <1.000, 1.000, 1.000> // *.3
  spotlight point_at <0,0,-1.5> radius 45 falloff 60 tightness 0
  translate  <0 , 0, 1.5>
}

Bob

"Lutz Kretzschmar" <lut### [at] stmuccom> wrote in message
news:387c972a.25351122@194.174.214.110...
> /*
> Hi All,
>
> while trying to track down a reported bug in Moray, I have either
> found a bug in POV-Ray 3.1g or there is something I don't
> understand<g>.
>
> The following is a simplified scene from Moray (I've converted the
> camera to LH coords) that demonstrates the problem. I make a union of
> a sphere and a light and copy that around. It seems to me that the
> lights are being placed at the incorrect position.
>
> Is this a bug or is my reasoning incorrect in thinking that the lights
> should be placed where the LightHolder object should be and that all
> the big spheres should be illuminated directly from above (the left)?
>
> Thanks,
>
> - Lutz
> */
>
> default { texture { pigment { rgb <1,0,0> } } }
>
> background { color <0.000,0.000,0.000> }
>
> camera {
>   location  <    -50.000,     0.0,      25.000>
>   look_at   <     0.00,       0.0,       0.0>
>   angle 30
> }
>
> // Declare a light source
> #declare Light001 = light_source {
>   <0.0, 0.0, 0.0>
>   color rgb <1.000, 1.000, 1.000>*0.3
>   translate  <0 , 0, 1.5>
> }
>
> // Declare a sphere at the same position
> #declare LightHolder = sphere {
>   <0.0, 0.0, 0.0>, 1
>     no_shadow
>     scale 0.3
>     translate  <0, 0, 1.5>
> }
>
> // Declare a union that contains both the light and the sphere as well
> as another sphere
> #declare Group001 = union {
>   object { Light001 }
>   object { LightHolder }
>
>   sphere { // a sphere to be illuminated
>     <0,0,0>,1
>   }
>   // Translate it out along X so that we can orbit the copies
>   translate  <10.0, 0.0, 0.0>
> }
>
> object {  Group001                 }
> object {  Group001 rotate 45.0*z   }
> object {  Group001 rotate 90.0*z   }
> object {  Group001 rotate 135.0*z  }
> object {  Group001 rotate 180.0*z  }
> object {  Group001 rotate 225.0*z  }
> object {  Group001 rotate 270.0*z  }
> object {  Group001 rotate 315.0*z  }
>
>
>
> - Lutz
>   email : lut### [at] stmuccom
>   Web   : http://www.stmuc.com/moray

Post a reply to this message

Hi omniVERSE, you recently wrote in povray.general:

> They are in the right place, just everything is getting illuminated by all the
> lights together which throws off your perception.  
Ahhh, so I'm interpreting what I see incorrectly. Oops. Thanks for the
sanity check<g>.

- Lutz
  email : lut### [at] stmuccom
  Web   : http://www.stmuc.com/moray

Post a reply to this message