POV-Ray : Newsgroups : povray.general : Area Light Setup : Re: Area Light Setup Server Time
4 Feb 2023 23:53:00 EST (-0500)
  Re: Area Light Setup  
From: Alain Martel
Date: 25 Jan 2023 10:46:40
Message: <63d14ee0$1@news.povray.org>
Le 2023-01-24 à 21:11, m@b a écrit :
> On 25/01/2023 5:17 AM, 88Keys wrote:
>> Hello.
>>
>> I'm trying to work with Area Lights, but I can't seem to orient them 
>> correctly.
>> I've been trying a <-50 , 0 , 50 > , <50 , 0 , 50 > and that doesn't 
>> seem to
>> illuminate my scene, so I tried a <-50 , 0 , 0 > , < 0 , 50 , 0 > in 
>> an attempt
>> to make the angles at 90 degrees to each other, but that doesn't seem 
>> to have
>> worked either.
>>
>> Any tips on how to generate a proper Area Light?  The documentation is 
>> a little
>> slim.  What I have developed seems pretty dull, too.
>>
>> Thanks very much.
>>
> 
> 
> 
> // author:  Matthew Bradwell
> // date:    2023
> //--------------------------------------------------------------------------
> #version 3.8;
> global_settings{ assumed_gamma 1.0 }
> #default{ finish{ ambient 0.1 diffuse 0.9 }}
> #default{texture{pigment{rgb<1,0,0>} finish{phong 1}}}
> // camera 
> ------------------------------------------------------------------
> camera {perspective  angle 11  location <0,10,-30>  look_at <0,2,0> 
> right x*image_width/image_height}
> 
> // Sky ------------------------------------------------------------------
> sky_sphere { pigment {rgb<0.3,0,1>*0.8}}
> 
> // ground 
> -------------------------------------------------------------------
> plane{ <0,1,0>, 0 texture{pigment{rgb<1,0.5,0.5>}}}
> 
> 
> sphere {<0,0,0>, 1 pigment {rgb<0.3,0,1>*0.8} translate<0,2,0>}
> 
> 
> // An area light (creates soft shadows)
> // WARNING: This special light can significantly slow down rendering times!
> light_source {
>    <0,0,0>             // light's position (translated below)
>    color rgb 1.0       // light's color
>    area_light
>    <20, 0, 0> <0, 0, 20>     // lights spread out across this distance 
> (x * z)
Placed flat in a 20 by 20 square.
>                  // The light is oriented in the horizontal plane 
(20x 
> * 20z)
>                  // Adding circular and orient below will ignore this

> orientation
>                  // and automaticaly orient the light to be 
> perpendicular to the
>                  // shadows it casts.
>    4, 4                // total number of lights in grid (4x*4z = 16

> lights)
That's a small array.
>    adaptive 0          // 0,1,2,3...
And using adaptive with it gives almost no benefit. With that adaptive 
value, you can use a 33 by 33 array with almost no performance hit.
>    jitter              // adds random softening of light
ESSENTIAL with such a small array
>    circular            // make the shape of the light circular
>    orient              // orient light
Make the light act as a spherical light source. This makes the 
orientation of the array irrelevant, just setting the extant of the light.
>    translate <40, 80, -40>   // <x y z> position of light
> }
>


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