clipka <ano### [at] anonymousorg> wrote:
> 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.

For different wavelength, reflectances and transmitances vary a lot. Is it
possible to set different value for different channels? I can save the radiosity
data and reuse for other wavelength? My objective is to save the render time for
different channels.

>
> > 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`.
>

Thanks. I build my own POV-Ray and change the DEPTH_MAX to 20000. Then the
recursion limit comes to be 255. Is it right?

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?

#version 3.7;
global_settings {
   assumed_gamma 1.0
   ambient_light 0.0
   adc_bailout 0.0
   max_trace_level 200

   radiosity {
      count 1500
      error_bound 0.1
      recursion_limit 100
      always_sample on

      gray_threshold 0.00
      brightness 1.0
      normal on
   }
}


Here it the *.ini file. I output the image as *.png. The transfer is linear? The
setting of Antialias impacts the result...the Antialias_gamma = 1.0 or 0.0?

Antialias = on
Antialias_Threshold = 0.0
Antialias_Depth = 5
Antialias_Gamma = 1.0
Input_File_Name = "canopy_ERE_NIR.pov"
File_Gamma = 1.0

width = 4000
height = 4000

Pov-ray uses radiosity to simulate the diffuse light. Compared with Monte Carlo,
physically we should get very similar result?


Thanks again.

Shouyang

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