--- ray/src/cv/bsdfrep.c	2012/10/23 05:10:42	2.4
+++ ray/src/cv/bsdfrep.c	2012/11/08 22:05:04	2.7
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrep.c,v 2.4 2012/10/23 05:10:42 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrep.c,v 2.7 2012/11/08 22:05:04 greg Exp $";
 #endif
 /*
  * Support BSDF representation as radial basis functions.
@@ -14,6 +14,9 @@ static const char RCSid[] = "$Id: bsdfrep.c,v 2.4 2012
 #include "rtio.h"
 #include "resolu.h"
 #include "bsdfrep.h"
+				/* active grid resolution */
+int			grid_res = GRIDRES;
+
 				/* coverage/symmetry using INP_QUAD? flags */
 int			inp_coverage = 0;
 				/* all incident angles in-plane so far? */
@@ -53,6 +56,8 @@ new_input_direction(double new_theta, double new_phi)
 		new_theta = -new_theta;
 		new_phi += 180.;
 	}
+	if ((theta_in_deg = new_theta) < 1.0)
+		return(1);		/* don't rely on phi near normal */
 	while (new_phi < 0)
 		new_phi += 360.;
 	while (new_phi >= 360.)
@@ -61,7 +66,6 @@ new_input_direction(double new_theta, double new_phi)
 		single_plane_incident = (round(new_phi) == round(phi_in_deg));
 	else if (single_plane_incident < 0)
 		single_plane_incident = 1;
-	theta_in_deg = new_theta;	/* assume it's OK */
 	phi_in_deg = new_phi;
 	if ((1. < new_phi) & (new_phi < 89.))
 		inp_coverage |= INP_QUAD1;
@@ -168,12 +172,39 @@ rev_rbf_symmetry(RBFNODE *rbf, int sym)
 	rev_symmetry(rbf->invec, sym);
 	if (sym & MIRROR_X)
 		for (n = rbf->nrbf; n-- > 0; )
-			rbf->rbfa[n].gx = GRIDRES-1 - rbf->rbfa[n].gx;
+			rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx;
 	if (sym & MIRROR_Y)
 		for (n = rbf->nrbf; n-- > 0; )
-			rbf->rbfa[n].gy = GRIDRES-1 - rbf->rbfa[n].gy;
+			rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
 }
 
+/* Rotate RBF to correspond to given incident vector */
+void
+rotate_rbf(RBFNODE *rbf, const FVECT invec)
+{
+	static const FVECT	vnorm = {.0, .0, 1.};
+	const double		phi = atan2(invec[1],invec[0]) -
+					atan2(rbf->invec[1],rbf->invec[0]);
+	FVECT			outvec;
+	int			pos[2];
+	int			n;
+#ifdef DEBUG
+	double	tdiff = 180./M_PI*fabs(acos(invec[2])-acos(rbf->invec[2]));
+	if (tdiff >= 1.5)
+		fprintf(stderr,
+			"%s: Warning - rotated theta differs by %.1f degrees\n",
+				progname, tdiff);
+#endif
+	for (n = 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);
+		rbf->rbfa[n].gx = pos[0];
+		rbf->rbfa[n].gy = pos[1];
+	}
+	VCOPY(rbf->invec, invec);
+}
+
 /* Compute volume associated with Gaussian lobe */
 double
 rbf_volume(const RBFVAL *rbfp)
@@ -190,7 +221,7 @@ ovec_from_pos(FVECT vec, int xpos, int ypos)
 	double	uv[2];
 	double	r2;
 	
-	SDsquare2disk(uv, (1./GRIDRES)*(xpos+.5), (1./GRIDRES)*(ypos+.5));
+	SDsquare2disk(uv, (1./grid_res)*(xpos+.5), (1./grid_res)*(ypos+.5));
 				/* uniform hemispherical projection */
 	r2 = uv[0]*uv[0] + uv[1]*uv[1];
 	vec[0] = vec[1] = sqrt(2. - r2);
@@ -208,8 +239,8 @@ pos_from_vec(int pos[2], const FVECT vec)
 
 	SDdisk2square(sq, vec[0]*norm, vec[1]*norm);
 
-	pos[0] = (int)(sq[0]*GRIDRES);
-	pos[1] = (int)(sq[1]*GRIDRES);
+	pos[0] = (int)(sq[0]*grid_res);
+	pos[1] = (int)(sq[1]*grid_res);
 }
 
 /* Evaluate RBF for DSF at the given normalized outgoing direction */
@@ -351,6 +382,7 @@ clear_bsdf_rep(void)
 	inp_coverage = 0;
 	single_plane_incident = -1;
 	input_orient = output_orient = 0;
+	grid_res = GRIDRES;
 }
 
 /* Write our BSDF mesh interpolant out to the given binary stream */
@@ -363,6 +395,7 @@ save_bsdf_rep(FILE *ofp)
 					/* finish header */
 	fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
 	fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
+	fprintf(ofp, "GRIDRES=%d\n", grid_res);
 	fputformat(BSDFREP_FMT, ofp);
 	fputc('\n', ofp);
 					/* write each DSF */
@@ -424,6 +457,10 @@ headline(char *s, void *p)
 		sscanf(s+9, "%d %d", &input_orient, &output_orient);
 		return(0);
 	}
+	if (!strncmp(s, "GRIDRES=", 8)) {
+		sscanf(s+8, "%d", &grid_res);
+		return(0);
+	}
 	if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
 		return(-1);
 	return(0);
@@ -438,6 +475,8 @@ load_bsdf_rep(FILE *ifp)
 	int		i;
 
 	clear_bsdf_rep();
+	if (ifp == NULL)
+		return(0);
 	if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
 			!input_orient | !output_orient) {
 		fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",