|
 |
I'm going to blame the couple of you reviving a dormant thread about
color to grey conversions for this! Always knock on wood after
mentioning a feature... ;-)
For those compiling versions of POV-Ray v3.8, be on the look out for
issues with the color to grey conversions. Issues which might affect
more than .grey, .gray functionality, though that's where I picked up
the problem.
The following code:
//---
#version 3.8;
global_settings { assumed_gamma 1.0 }
#declare Color = rgb <0.0,1.0,0.0>;
#declare FnP = function { pigment { Color } }
#debug concat("\n\nred = ",str(Color.red,2,3)," \n")
#debug concat("green = ",str(Color.green,2,3)," \n")
#debug concat("blue = ",str(Color.blue,2,3)," \n")
#debug concat("filter = ",str(Color.filter,2,3)," \n")
#debug concat("transmit = ",str(Color.transmit,2,3)," \n")
#debug concat("gray = ",str(Color.gray,2,3)," \n")
#debug concat("grey = ",str(Color.grey,2,3)," \n")
#debug concat("\nFnGray = ",str(FnP(0,0,0).gray,2,3)," \n")
#debug concat("FnGrey = ",str(FnP(0,0,0).grey,9,16)," \n")
// .hf ?
// Most sensitive to red ? Using all three channels or?
#declare FnHf = function { FnP(0,0,0).hf }
#debug concat("FnHf = ",str(FnHf(0,0,0),9,16)," \n")
//Sanity check not something aside from .grey
#debug concat("FnVal0 = ",str(0.9876,2,3)," \n")
#debug concat("FnVal1 = ",str(0.98761,9,-1)," \n")
#debug concat(" ","\n\n")
//---
should generate:
red = 0.000
green = 1.000
blue = 0.000
filter = 0.000
transmit = 0.000
gray = 0.589
grey = 0.589
FnGray = 0.589
FnGrey = 0.5890000000000000
FnHf = 0.0039062470588235
FnVal0 = 0.988
FnVal1 = 0.987610
but the gray/grey values reported are wrong (for as right as they get)
for recent code versions and compiles.
First, thought it must be something in my povr changes because I have a
v38 compile done on New Year's Eve which works. After chasing ghosts for
the better part of a day, I finally tried re-compiling v3.8 master again
and to my surprise it too now fails.
I've since found a commit at c341c943 which works and a commit 5219e71c
(1) that fails - with 15 commits between. I should be able to zero in on
the issue, but unless I get lucky, it will take time.
(1) - Nine before Christoph's last v3.8 commit.
My guess at the moment is there is some dependency which changed in a
way breaking code. In broken versions, I don't seem to reach the
conversion code. Clang++ compiles mirror the g++ behavior.
FWIW! Expect it very much hit or miss whether - or when - others might
see this issue. Be aware of it. I'm unsure of the scope beyond the
.grey/.gray feature and using Ubuntu 20.04.1.
Bill P.
Post a reply to this message
|
|
