I have done an AA test with following scene:


#declare contrast=1;

camera{
location <0,1,0>
look_at 0}

plane{y,0 
   pigment{onion
           pigment_map{
                   [0 rgb 0]
                         [0.5 rgb 0]
                         [0.5 rgb contrast] 
                         [1 rgb contrast]
                         }
                scale .02
                }
         finish{ambient 1}
         
         rotate y*34
         }
         
All renderings were done in 320x240, +J0 with povray 3.1

Here are the results (the numbers in the tables are the Smpls/Pxl that pov 
reports in the statistics):
+AM1 +R3
--------
                +A0.1     +A0.3     +A0.6
contrast=1.0     8.50      8.50      7.93
contrast=0.5     8.50      7.93      7.13
contrast=0.1     7.39      6.67      1.00


+AM1 +R6
--------
               +A0.1     +A0.3     +A0.6
contrast=1.0   35.35     33.91     31.64
contrast=0.5   34.69     31.64     28.89
contrast=0.1   29.46     26.74      1.00

+AM2 +R3
--------
                +A0.1     +A0.3     +A0.6
contrast=1.0    16.05     16.05     16.05
contrast=0.5    16.05     16.05     16.05
contrast=0.1    16.05     16.05      1.01

+AM2 +R3
--------
                +A0.1    +A0.6
contrast=1.0   136.64   136.64
contrast=0.1   136.64     1.01

This shows that with Method 1 it does matter for the recursion how big the 
contrast between the pixels is. Though 6.67 Samples/Pixels with +A0.3 and a 
nearly all black picture seems very high to me.

On the other side with Method 2 it does not matter how much the contrast 
is, pov will always use the same recursion depth if the threshold is 
reached. I think this definiteley could/should be improved.

- Micha

Post a reply to this message