POV-Ray : Newsgroups : povray.advanced-users : Why don't shadows get blurry after a certain distance? ("Distance Field Sha= : Re: Why don't shadows get blurry after a certain distance? ("Distance Field Sha= Server Time
11 Aug 2022 10:51:32 EDT (-0400)
  Re: Why don't shadows get blurry after a certain distance? ("Distance Field Sha=  
From: Alain Martel
Date: 4 Jun 2022 09:14:31
Message: <629b5ab7$1@news.povray.org>
Le 2022-06-03 à 23:53, HackerDaGreat57 a écrit :
> I was just rendering the Biscuit sample and found something strange: The shadows
> on objects don't get blurrier as they get farther away from the object.
> 
> If your mind is completely foggy and you are confused and don't know what I'm
> talking about, take a look at this Unreal Engine 4 documentation page:
>
https://docs.unrealengine.com/4.27/en-US/BuildingWorlds/LightingAndShadows/RayTracedDistanceFieldShadowing/
> 

That scene use a point light. That kind of light always produce sharp 
shadows without any blurring. It's an infinitely small light source.

The used light is :
light_source {<-140,200, 300> rgb <1.0, 1.0, 0.95>*1.5}

To have blurring shadows, you need to use an area_light.
Change it to :
#declare Size = 3;
light_source {<-140,200, 300> rgb <1.0, 1.0, 0.95>*1.5 area_light Size*x 
Size*z 17 17 jitter adaptive 0 circular orient}

to simulate a spherical light source with a diameter of 3 units.
The «adaptive 0» makes it render much faster by using an adaptive 
sampling method.
Change «Size» to change the broadness of the penumbra, or how much the 
shadow get blurry.


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