--- ray/src/util/genBSDF.pl	2014/04/24 23:08:08	2.47
+++ ray/src/util/genBSDF.pl	2014/07/09 15:03:11	2.48
@@ -1,5 +1,5 @@
 #!/usr/bin/perl -w
-# RCSid $Id: genBSDF.pl,v 2.47 2014/04/24 23:08:08 greg Exp $
+# RCSid $Id: genBSDF.pl,v 2.48 2014/07/09 15:03:11 greg Exp $
 #
 # Compute BSDF based on geometry and material description
 #
@@ -88,6 +88,9 @@ while ($#ARGV >= 0) {
 }
 # Check that we're actually being asked to do something
 die "Must have at least one of +forward or +backward\n" if (!$doforw && !$doback);
+# Issue warning for unhandled reciprocity case
+print STDERR "Warning: recommend both +forward and +backward with -t3" if
+		($tensortree==3 && !($doforw && $doback));
 # Get scene description and dimensions
 
 if ( $mgfin ) {