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"tasuki" <nomail@nomail> wrote:
> Hello Alain,
>
> thanks for your answer.
>
> Alain <ele### [at] netscape net> wrote:
> > This is due to the fact that area_light are composed of several point_lights
> > disposed in a regular array. Some shadowed points may be in view of all of
> > those points.
>
> Yes, I figured out this was the problem, but I am not sure how to get rid of
> it ;)
>
> > The use of jitter can help hide this, as for each points tested, the location
> > of each element is slightly shifted randomly from it's original position for
> > the shadow evaluation. This random noise is normaly unnoticeable.
>
> I did use jitter, too.
> Well, let me clarify, this is my test scene:
>
>
> #include "colors.inc"
> #include "textures.inc"
> plane { y, 0
> pigment { rgb .8 }
> finish { reflection .05 }
> }
> cylinder { <0,0,0>,<0,1,0>,.03
> texture { Chrome_Metal }
> }
> #declare qualight=clock;
> light_source { <6, 4, 0> White
> area_light <3, 0, 0>, <0, 0, 3>, qualight, qualight
> jitter
> circular orient
> }
> camera {
> location <0, 2, -2>
> look_at <-1.2, 0, 0>
> }
>
>
> You can see the result here: http://www.tasuki.org/povray/arealights.png
>
> For some number of lights, it looks ok... but the problem appears again when
> I have more sticks at different distances from the area light...
Your area light is *way* too wide compared to the item it shines on. You've
got a cylinder 0.03 in radius and, in the 50 lights scenario, a light every
0.06. Obviously you end up with two shadows divided by a lighter zone.
Simply cut down on the area light size (i.e. <3, 0, 0>, <0, 0, 3> ) to
something more in tune with the target object size.
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