Am 24.03.2017 um 00:14 schrieb muyu:

> For each leaf, 0.4957 is scatted directly. 0.4409 is transmitted and scatted. So
> as I understood, I should not use any filter. The two sides diffuse is the right
> choice. Am I right?

Yes, you are.

> So it means 20 times of recursion is not enough? Is it
> possible to set larger value.Now for me, the rendering time is still
> acceptable.

If building your own modified POV-Ray binaries is an option, you could
edit the definition of DEPTH_MAX in `source/core/lighting/radiosity.h`.


>>> The reflectance of each pixel was calculated relative to the reference panel
>>> with the same light source and camera setup
>>> // the reference panel--------------------------------------------------------
>>> plane { <0,0,1>, 0
>>>         texture{ pigment{color rgb<0, 1, 0>}
>>>                  finish {ambient 0 diffuse 1.0 0.0 conserve_energy}
>>>                } // end of texture
>>>       } // end of plane
>>>
>>> Reflectance = (Simulation/Reference)^2.2
>>
>> Are you using File_Gamma=2.2, or why is that exponent in there?
> 
> Here I did not set File_Gamma = 1.0. But the result should be same if I use this
> Reflectance = (Simulation/Reference)^2.2.

Note that for most output file formats (including JPEG and PNG) POV-Ray
3.7 uses the sRGB encoding transfer function by default (and for those
where it doesn't, it defaults to linear output or the ITU-R BT.709
transfer function). For the power-law with an exponent of 2.2 to give
correct results, you should use `File_Gamma=2.2`. (Or instead apply the
sRGB decoding transfer function to sim and reference separately, and
then divide.)

Also, make sure the software you are using to compute the reflectance
does indeed operate on gamma-encoded values.

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