--- ray/src/util/genBSDF.pl	2017/06/08 15:37:15	2.77
+++ ray/src/util/genBSDF.pl	2018/04/19 17:02:13	2.80
@@ -1,5 +1,5 @@
 #!/usr/bin/perl -w
-# RCSid $Id: genBSDF.pl,v 2.77 2017/06/08 15:37:15 greg Exp $
+# RCSid $Id: genBSDF.pl,v 2.80 2018/04/19 17:02:13 greg Exp $
 #
 # Compute BSDF based on geometry and material description
 #
@@ -116,7 +116,7 @@ while ($#ARGV >= 0) {
 		shift @ARGV;
 	} elsif ("$ARGV[0]" =~ /^[-+]C/) {
 		$docolor = ("$ARGV[0]" =~ /^\+/);
-	} elsif ("$ARGV[0" =~ /^[-+]a/) {
+	} elsif ("$ARGV[0]" =~ /^[-+]a/) {
 		$dorecip = ("$ARGV[0]" =~ /^\+/);
 	} elsif ("$ARGV[0]" =~ /^[-+]f/) {
 		$doforw = ("$ARGV[0]" =~ /^\+/);
@@ -190,7 +190,8 @@ my $CIEuv =	'Xi=.5141*Ri+.3239*Gi+.1620*Bi;' .
 		'Yi=.2651*Ri+.6701*Gi+.0648*Bi;' .
 		'Zi=.0241*Ri+.1229*Gi+.8530*Bi;' .
 		'den=Xi+15*Yi+3*Zi;' .
-		'uprime=4*Xi/den;vprime=9*Yi/den;' ;
+		'uprime=if(Yi,4*Xi/den,4/19);' .
+		'vprime=if(Yi,9*Yi/den,9/19);' ;
 my $FEPS = 1e-5;
 my $ns = 2**$ttlog2;
 my $nx = int(sqrt($nsamp*($dim[1]-$dim[0])/($dim[3]-$dim[2])) + 1);