> > Surprisingly, the reflectance increases very very silightly even when I set
> > recursion at 255. Here is the setting of the radiosity. I am wondering if I can
> > further increase the reflectance. It is still 5 to 10% underestimate. Still some
> > light is not absorbed?
>
> A maximum recursion setting of 255 should be more than enough; I'm a bit
> at a loss where the remaining light is swallowed -- are you sure your
> reference is correct?

The reference is the esemble of several radiative transfer model based on Monte
Carlo. (RAMI-online, http://romc.jrc.ec.europa.eu/Home.php)

If Pov-ray is physically un-biased, consistent results are expected (right?). A
slight 5 to 10% underestimate is found. I guess there are two possibilities:

1) Still some light is not absorbed. Possible?

2) The calibration factor may be wrong. I simulated the reference panel and set
the diffuse as 1.0. The value is the same over different viewing angles. But I
found that when I increased the height of the light source, the value may change
from 239 to 240 (why?). Then the reflectance in the scene is caculated by diving
this calibration factor. Is this the right way?

Thanks a lot for your patience.

Shouyang

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