One of the limitations of area lights is that the light they cast is different
depending on the angle. What is the best way to create a light that casts soft
shadows, but does so equally in each direction?

-Mike

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SharkD wrote:
> One of the limitations of area lights is that the light they cast is different
> depending on the angle. What is the best way to create a light that casts soft
> shadows, but does so equally in each direction?
> 
	Add "orient" to your area light and it will turn to always face in
the right direction.

		Jerome
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=?ISO-8859-1?Q?=22J=E9r=F4me_M=2E_Berger=22?= <jeb### [at] freefr> wrote:
>  Add "orient" to your area light and it will turn to always face in
> the right direction.

This doesn't eliminate the problem whereby the light source only casts the
shadows properly in a single direction.

-Mike

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"SharkD" <nomail@nomail> wrote in message 
news:web.493bcdf0991b1dd0bb691c840@news.povray.org...
> =?ISO-8859-1?Q?=22J=E9r=F4me_M=2E_Berger=22?= <jeb### [at] freefr> wrote:
>>  Add "orient" to your area light and it will turn to always face in
>> the right direction.
>
> This doesn't eliminate the problem whereby the light source only casts the
> shadows properly in a single direction.

uhm... that's *exactly* what it eliminates, no?

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com

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"Zeger Knaepen" <zeg### [at] povplacecom> wrote:
> uhm... that's *exactly* what it eliminates, no?

No, it doesn't. I want the light source to light an entire scene evenly.
Rotating the light source just means the angle has *changed*. It doesn't
*increase* the number of angles. It still only points to one location.

-Mike

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SharkD wrote:
> "Zeger Knaepen" <zeg### [at] povplacecom> wrote:
>> uhm... that's *exactly* what it eliminates, no?
> 
> No, it doesn't. I want the light source to light an entire scene evenly.
> Rotating the light source just means the angle has *changed*. It doesn't
> *increase* the number of angles. It still only points to one location.

"orient" rotates the light to face in the right direction *individually for
every ray*. Each time the shadow is calculated, the area light will be
pointing at the point being tested.

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Nicolas Alvarez <nic### [at] gmailcom> wrote:
> "orient" rotates the light to face in the right direction *individually for
> every ray*. Each time the shadow is calculated, the area light will be
> pointing at the point being tested.

Oh! Awesome! I didn't realize that.

-Mike

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Nicolas Alvarez wrote:
> SharkD wrote:
> 
>>"Zeger Knaepen" <zeg### [at] povplacecom> wrote:
>>
>>>uhm... that's *exactly* what it eliminates, no?
>>
>>No, it doesn't. I want the light source to light an entire scene evenly.
>>Rotating the light source just means the angle has *changed*. It doesn't
>>*increase* the number of angles. It still only points to one location.
> 
> 
> "orient" rotates the light to face in the right direction *individually for
> every ray*. Each time the shadow is calculated, the area light will be
> pointing at the point being tested.
> 
Sounds like you want to broaden the area of the 'grid' of lights.  Best 
results are usually around 10% of the distance to the light source.  If 
you want more softness than that you can have by increasing the area of 
the grid, but need to seriousless increase the 'number' of lights in the 
grid too.  Use 'adaptive' in that case.  Remember this only affects 
shadows though, the highlight will still be a point.  This features gets 
good effects in a broad range of normal cases.  THe serach for 
convincing soft diffuse lighting has lead many to improvise 'dome 
lighting' systems.  Just search the ng's

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"SharkD" <nomail@nomail> wrote:
> One of the limitations of area lights is that the light they cast is different
> depending on the angle. What is the best way to create a light that casts soft
> shadows, but does so equally in each direction?
>
> -Mike

Adding the "circular" and "orient" keywords to your area lights will do exactly
what you're looking for.

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