|
|
See thread "FYI. Watch out for bad color to grey value conversions." in
povray.unix.
Macro Light_Color_Filtered() in Lightsys IV uses .gray, so scenes using
this macro are unlikely to have proper lighting under the latest 3.8
build. This situation is temporary, until 3.8 is debugged; but in the
meantime, this workaround should work:
First, add this macro to lightsys.inc:
#macro Light_DotGray (C)
(0.297 * C.red + 0.589 * C.green + 0.114 * C.blue)
#end
Then change the Light_Color() call in macro Light_Color_Filtered() to:
Light_Color(Lct*Flt,Lm*Light_DotGray(filtered)/Light_DotGray(Lct))
I haven't tested this yet, because I wanted to get the info out quickly,
but it looks straightforward. Also, this workaround uses the internal
POV-Ray grayscale formula, which will keep the old behavior, but was
coded before gamma handling was seriously examined. A more accurate
formula can be found in the p.unix thread, although that formula is
accurate only for the sRGB/BT.709 color systems (which yours probably is
anyway).
Post a reply to this message
|
|