feat(genssky): Taoning added -L option to specify illuminance

doc/man/man1/genssky.1

@@ -1,11 +1,11 @@
-.\" RCSid $Id: genssky.1,v 1.3 2024/08/02 18:47:25 greg Exp $
+.\" RCSid $Id: genssky.1,v 1.4 2024/10/09 21:10:54 greg Exp $
 .TH "GENSSKY" "1" "8/31/24" "RADIANCE" ""
 .SH "NAME"
 genssky - generates a RADIANCE description of the spectral daylight sources
 .br
 
 .SH "SYNOPSIS"
-\fBgenssky month day hour [-y year] [-d AOD] [-c cloud_cover] [-l file] [-p dir] [-g grefl] [-n nproc] [-r res] [-f outname]\fR
+\fBgenssky month day hour [-y year] [-d AOD] [-c cloud_cover] [-l file] [-p dir] [-g grefl] [-L dir_norm_illum dif_hor_illum] [-n nproc] [-r res] [-f outname]\fR
 .br
 
 .SH "DESCRIPTION"
@@ -65,6 +65,9 @@ Non-clear conditions are modeled by linearly interpolating between clear sky and
 \fB-y	     Set year to invoke a more accurate algorithm to calculate solar angles, default=0.
 .br
 
+\fB-L	     Set direct normal and diffuse horizontal illuminance value.
+.br
+
 
 .SH "EXAMPLES"
 To generate a clear sky for March 2th at 3:15pm standard time at a site latitude of 42 degrees, 108 degrees west longitude, and a 110 degrees standard meridian, using 8 threads:
@@ -81,6 +84,13 @@ For the same sky but with 100 percent total cloud cover:
 
 .br
 
+For the same sky but with direct normal and diffuse horizontal illuminance of 80000 and 8000 lux:
+.br
+
+  genssky 3 2 15.25 -a 42 -o 108 -m 110 -n 8 -L 80000 8000
+
+.br
+
 
 .SH "FILES"
 /usr/local/lib/ray/mie_ca.dat

doc/notes/ReleaseNotes

@@ -2742,3 +2742,6 @@ Added accurate conversion of hyperspectral pictures to ra_xyze.
 Added hyperspectral picture conversion to ra_tiff, with accurate
 color when targeting 16-bit/comp., LogLuv, and float utput,
 and the approximate method for 24-bit RGB.
+
+Taoning added genssky -L option to specify global and diffuse
+illuminance values for output calibration.