--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bin/compamb.pl	Sun Dec 11 23:02:02 2011 +0000
@@ -0,0 +1,86 @@
+#!/bin/perl
+# RCSid: $Id: compamb.csh,v 3.7 2008/08/25 04:50:32 greg Exp $
+#
+# Compute best ambient value for a scene and append to rad input file
+# This is a re-write of Greg's CSH script compamb.csh
+# (c) Axel Jacobs, Nov 2011
+
+use strict;
+use warnings;
+use File::Temp qw/ tempdir /;
+
+my $doexpos = 0;
+my $docolor = 0;
+my $radfile;
+my $oct;
+
+sub usage() {
+	print "Usage: $0 [-e] [-c] rad_input_file.rad\n";
+	exit 1;
+}
+
+while ($#ARGV > 0) {
+	$_ = shift @ARGV;
+	if (m/-e/) {
+		$doexpos = 1;
+	} elsif (m/-c/) {
+		$docolor = 1;
+	} else {
+		&usage;
+	}
+}
+
+if ($#ARGV == 0) {
+	$radfile = $ARGV[0];
+	if (! -f $radfile) {
+		die ("Cannot open Radiance input file $ARGV[0]\n");
+	}
+} else {
+	&usage;
+}
+
+my $td = tempdir( CLEANUP => 1 );
+#set oct=`rad -w -s -e -v 0 $argv[1] QUA=High AMB=$tf.amb OPT=$tf.opt | sed -n 's/^OCTREE= //p'`
+my $radout = `rad -w -s -e -v 0 $radfile QUA=High AMB=$td/compamb.amb OPT=$td/compamb.opt`;
+exit 1;
+#...my $oct = sed -n 's/^OCTREE= //p'`
+my $rpictargs = '-av 0 0 0 -aw 16 -dv- -S 1 -x 16 -y 16 -ps 1';
+system "rad -n -s -V $radfile | rpict @$td/compamb.opt $rpictargs $oct | ra_rgbe - '\!pvalue -h -H -d' > $td/compamb.dat";
+#rad -n -s -V $argv[1] \
+	#| rpict @$tf.opt -av 0 0 0 -aw 16 -dv- -S 1 -x 16 -y 16 -ps 1 $oct \
+	#| ra_rgbe - '\!pvalue -h -H -d' > $tf.dat
+
+#echo \# Rad input file modified by $0 `date` >> $argv[1]
+my $now = localtime();
+open (FHrad, ">>$radfile") or
+		die("Unable to append to file $radfile\n");
+print FHrad "# Rad input file modified by $0 $now";
+
+if ($doexpos == 1) {
+	my $expo = `total -u $td/compamb.dat | rcalc -e '$1=2/(.265*$1+.670*$2+.065*$3)'`;
+	#chomp $expo;
+	#(echo -n 'EXPOSURE= '; \
+		#total -u $tf.dat | rcalc -e '$1=2/(.265*$1+.670*$2+.065*$3)') \
+		#>> $argv[1]
+	print FHrad "EXPOSURE= $expo\n";
+}
+
+#lookamb -h -d $tf.amb | rcalc -e '$1=$10;$2=$11;$3=$12' >> $tf.dat
+system ("lookamb -h -d $td/compamb.amb | rcalc -e '$1=$10;$2=$11;$3=$12' >> $td/compamb.dat");
+
+#set lavg=`rcalc -e '$1=lum;lum=.265*$1+.670*$2+.065*$3;cond=lum-1e-5' $tf.dat | total -m -p`
+my $lavg = `rcalc -e '$1=lum;lum=.265*$1+.670*$2+.065*$3;cond=lum-1e-5' $td/compamb.dat | total -m -p`;
+
+my $av = "$lavg $lavg $lavg";
+if ($docolor == 1) {
+	my $cavg = `total -m $td/compamb.dat`;
+	my ($ravg, $gavg, $bavg) = split(/\t/, $cavg);
+	my $sf = $lavg / (.265*$ravg + .670*$gavg + .065*$bavg);
+	#my $av = `rcalc -n -e "r=$ravg;g=$gavg;b=$bavg;sf=$lavg/(.265*r+.670*g+.065*b)" -e '$1=sf*r;$2=sf*g;$3=sf*b'`)
+	my $av = "$sf*$ravg $sf*$gavg $sf*$bavg";
+}
+
+print FHrad "render= -av $av";
+close (FHrad);
+
+#EOF