"Nathan Kopp" <pov### [at] nkoppmailshellcom> wrote:

> Using more photons would probably improve the photon brightness estimate and
> increase the brightness.
>
> -Nathan

Hi, I'm also trying to find out how photons are working.
The first thing i noticed, photons without radiosity are senseless. Somehow
they look unrealistic and they are not bright enough. But maybe thats a
reason of my scene.
If You want to have more brighter photons You can do the following :

Multipy the color-statement in You lightsource by 2 or 3 and render the
image with save photons turned on. Then change back the light intensity to
normal, render again with photons, but load the photon map this time. Your
scene will be illuminate like normal, but much brighter photons will
appear.
The image in
http://news.povray.org/web.415ab576364ff56a6b3522e90%40news.povray.org was
created like that.

To make it more easy I'm using some little macros to switch between some
radiosity and photon setting.

#declare Radiosity         = off; // on/off  switch radiosity, settings
  #if (Radiosity)                 // below
    Radiosity_Brightness (2, 1, on, on, 1 )
  #end
#declare Photons           = off; // on/off  switch photons, settings below
#declare P_Preview         = off;
  #if (Photons)
    Photons_Quality ( 0.01, 1, 5, 1)
  #end


//#macro Radiosity_Brightness ( type, brightness, normal, media, File )
//
//    Type       : [0]  = Radiosity_Default
//                 [1]  = Radiosity_Debug
//                 [2]  = Radiosity_Fast
//                 [3]  = Radiosity_Normal
//                 [4]  = Radiosity_2Bounce
//                 [5]  = Radiosity_Final
//                 [6]  = Radiosity_OutdoorLQ
//                 [7]  = Radiosity_OutdoorHQ
//                 [8]  = Radiosity_OutdoorLight
//                 [9]  = Radiosity_IndoorLQ
//                 [10] = Radiosity_IndoorHQ
//
//    Brightness : [value] is multiplied with brightness=1
//
//    normal     : [on/off] Radiosity with normal
//
//    media      : [on/off] Radiosity with media
//
//    File       : [0]  = do no file operation
//                 [1]  = saves a specified radiosity.txt
//                 [2]  = loads a specified radiosity.txt
//
#macro Radiosity_Brightness (Rt, Rb, Normal, Media, RFile)
  #include "rad_def.inc"
  global_settings
  { assumed_gamma 2.2
    ambient_light color rgb <1.0,1.0,1.0>
    max_trace_level 4
    radiosity { Rad_Settings(Rt, Normal,Media)
                brightness 1*Rb
                normal Normal
                media Media
                  #switch (RFile)
                  #case (0)
                  #break
                  #case (1)
                    save_file "C:TEMPScene_radiosity.txt"
                  #break
                  #case (2)
                    load_file "C:TEMPScene_radiosity.txt"
                  #break
                  #end } }
#end





//#macro Photons_Quality (Spacing, Jitter, max_trace_level, File)
//
//    Spacing    : same as spacing [0.01..0.05]
//
//    Jitter     : same as jitter [0..1]
//
//    max_tr_lev : max_trace_level
//
//    File       : [0]  = do no file operation
//                 [1]  = saves a specified photons.txt
//                 [2]  = loads a specified photons.txt
//
////#declare Photons       = off;    // on/off  switch photons, settings
below
////  #if (Photons)
////    Photons_Quality ( 0.01, 1, 5, 1)
////  #end
//
//
//

#macro Photons_Quality (Sp, Ji, mtl, PFile)
  global_settings { assumed_gamma 2.2
                    photons {
                    spacing Sp           // specify the density of photons
                    gather 35, 250       // amount of photons gathered
                                         // during render [20, 100]
                    media  35, 250       // media photons max_steps
[,factor]
                    jitter Ji            // jitter phor photon rays
                    max_trace_level mtl  // optional separate
max_trace_level
                    adc_bailout 0.01     // see global adc_bailout
                    //autostop 0         // photon autostop option
                    //radius 10          // manually specified search radius
                    // (---Adaptive Search Radius---)
                    //steps 1
                    //expand_thresholds 0.2, 40
                    #switch (PFile)
                      #case (0)
                      #break
                      #case (1)
                        save_file "C:TEMPScene_photons.txt"
                      #break
                      #case (2)
                        load_file "C:TEMPScene_photons.txt"
                      #break
                    #end}}
#end




Shu.

Post a reply to this message