Still working my way thru the tutorial...

I have the camera and light_source inside a white box.
When I put the light_source close to one side of
the box, that side is rendered very dark.

This really surprises me.
Could someone please explain why this is, so that
I can anticipate this kind of behavior in the future?

The doc. says:
A pointlight ... illuminates  everything in the scene
equally no matter how far away from the light source
it may be.

Here is the .pov file:
-------------------------
#include "colors.inc"
camera {
    location <-10, 8, -19>  look_at <0, 5, 0>  angle 75
}
light_source { <-.3, 1, .3> color rgb 0.5 atmosphere off }

box { <-20,  0, -20>, <20, 20, 20>
    pigment { color White }
    finish { ambient 0.2 diffuse 0.5 }
}
// x-y-z axes
cylinder { -100*x, 100*x, .03  pigment {Gold} finish {ambient .8}}
cylinder { -100*z, 100*z, .03  pigment {Gold} finish {ambient .8}}
cylinder { -100*y, 100*y, .03  pigment {Gold} finish {ambient .8}}
--------------------------
Note how much darker the floor is.
If you move the light to <-.3, 19, .3>, the ceiling will be dark.
Change the value of "diffuse" and things don't change much.
Change the value of "ambient" and the floor is still
a lot darker than the walls.

Alan

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