folkert <fol### [at] vanheusdencom> wrote:
> Hi,

> I'm trying to render my appartment is realistic as possible. So for that I put a
> huge sun above it:

> // distance: 150.000.000km, diameter 1.932.000km
> light_source { <0, 15000000000000, 0> color White
>                 area_light <193200000000, 0, 0>, <0, 0, 193200000000>, 5, 5
> adaptive 1 jitter
>                 looks_like {
>                         sphere { <0, 15000000000000 + 193200000000 / 2, 0>,
> 193200000000/2 pigment { color rgb<0.85,1.0,0.85> } }
>                 }
> }

  Note that you will not get any visible difference by using those values
or using values which are eg. five orders of magnitude smaller. What you
*could* potentially get with such huge values, however, is rendering
artifacts due to the limited accuracy of floating point values. (After
all, you are using values like 15000000000000 in conjunction with values
that probably are less than 1, in other words, you are dealing with over
15 digits of accuracy, which is the size of the mantissa of a double
precision floating point number. Rendering artifacts are a real possibility.)

> Now the main room (render the test.pov for that) is rather dark. Much darker
> then  it was in reality. Of course I could add an extra light just before the
> window but that's faking it too much.
> What would be the solution?

  Real-life rooms are much brighter because the sunlight bounces from the
walls and other surfaces, further illuminating the rest of the room (and
even this reflected light will bounce a second time, although it will be
significantly dimmer, but still contributes to the overall brightness;
even the third bounce might contribute a bit).

  The only way to simulate that in a scene is to use radiosity. This will
make the rendering significantly slower, and getting all the radiosity
parameters correct can be an arduous task, but the end result can be very
realistic.

-- 
                                                          - Warp

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