--- ray/src/cv/bsdfrep.c	2012/11/09 02:16:29	2.8
+++ ray/src/cv/bsdfrep.c	2012/11/22 06:07:17	2.11
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrep.c,v 2.8 2012/11/09 02:16:29 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrep.c,v 2.11 2012/11/22 06:07:17 greg Exp $";
 #endif
 /*
  * Support BSDF representation as radial basis functions.
@@ -82,7 +82,7 @@ new_input_direction(double new_theta, double new_phi)
 int
 use_symmetry(FVECT vec)
 {
-	double	phi = get_phi360(vec);
+	const double	phi = get_phi360(vec);
 
 	switch (inp_coverage) {
 	case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
@@ -189,7 +189,7 @@ rotate_rbf(RBFNODE *rbf, const FVECT invec)
 	int			pos[2];
 	int			n;
 
-	for (n = rbf->nrbf; n-- > 0; ) {
+	for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
 		ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy);
 		spinvector(outvec, outvec, vnorm, phi);
 		pos_from_vec(pos, outvec);
@@ -485,6 +485,10 @@ load_bsdf_rep(FILE *ifp)
 		rbfh.invec[0] = getflt(ifp);
 		rbfh.invec[1] = getflt(ifp);
 		rbfh.invec[2] = getflt(ifp);
+		if (normalize(rbfh.invec) == 0) {
+			fprintf(stderr, "%s: zero incident vector\n", progname);
+			return(0);
+		}
 		rbfh.vtotal = getflt(ifp);
 		rbfh.nrbf = getint(4, ifp);
 		newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +