--- ray/src/cv/bsdfinterp.c	2013/09/26 17:05:00	2.12
+++ ray/src/cv/bsdfinterp.c	2013/10/23 03:41:39	2.15
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfinterp.c,v 2.12 2013/09/26 17:05:00 greg Exp $";
+static const char RCSid[] = "$Id: bsdfinterp.c,v 2.15 2013/10/23 03:41:39 greg Exp $";
 #endif
 /*
  * Interpolate BSDF data from radial basis functions in advection mesh.
@@ -94,10 +94,14 @@ on_edge(const MIGRATION *ej, const FVECT ivec)
 	cos_a = DOT(ej->rbfv[0]->invec, ivec);
 	if (cos_a <= 0)
 		return(0);
+	if (cos_a >= 1.)		/* handles rounding error */
+		return(1);
 
 	cos_b = DOT(ej->rbfv[1]->invec, ivec);
 	if (cos_b <= 0)
 		return(0);
+	if (cos_b >= 1.)
+		return(1);
 
 	cos_aplusb = cos_a*cos_b - sqrt((1.-cos_a*cos_a)*(1.-cos_b*cos_b));
 	if (cos_aplusb <= 0)
@@ -260,8 +264,9 @@ get_interp(MIGRATION *miga[3], FVECT invec)
 
 /* Advect and allocate new RBF along edge */
 static RBFNODE *
-e_advect_rbf(const MIGRATION *mig, const FVECT invec)
+e_advect_rbf(const MIGRATION *mig, const FVECT invec, int lobe_lim)
 {
+	double		cthresh = FTINY;
 	RBFNODE		*rbf;
 	int		n, i, j;
 	double		t, full_dist;
@@ -286,11 +291,17 @@ e_advect_rbf(const MIGRATION *mig, const FVECT invec)
 		rbf->next = NULL; rbf->ejl = NULL;
 		return(rbf);
 	}
-	t /= full_dist;	
+	t /= full_dist;
+tryagain:
 	n = 0;					/* count migrating particles */
 	for (i = 0; i < mtx_nrows(mig); i++)
 	    for (j = 0; j < mtx_ncols(mig); j++)
-		n += (mtx_coef(mig,i,j) > FTINY);
+		n += (mtx_coef(mig,i,j) > cthresh);
+						/* are we over our limit? */
+	if ((lobe_lim > 0) & (n > lobe_lim)) {
+		cthresh = cthresh*2. + 10.*FTINY;
+		goto tryagain;
+	}
 #ifdef DEBUG
 	fprintf(stderr, "Input RBFs have %d, %d nodes -> output has %d\n",
 			mig->rbfv[0]->nrbf, mig->rbfv[1]->nrbf, n);
@@ -311,14 +322,16 @@ e_advect_rbf(const MIGRATION *mig, const FVECT invec)
 	    float		mv;
 	    ovec_from_pos(v0, rbf0i->gx, rbf0i->gy);
 	    for (j = 0; j < mtx_ncols(mig); j++)
-		if ((mv = mtx_coef(mig,i,j)) > FTINY) {
+		if ((mv = mtx_coef(mig,i,j)) > cthresh) {
 			const RBFVAL	*rbf1j = &mig->rbfv[1]->rbfa[j];
-			double		rad1 = R2ANG(rbf1j->crad);
+			double		rad2;
 			FVECT		v;
 			int		pos[2];
-			rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal;
-			rbf->rbfa[n].crad = ANG2R(sqrt(rad0*rad0*(1.-t) +
-							rad1*rad1*t));
+			rad2 = R2ANG(rbf1j->crad);
+			rad2 = rad0*rad0*(1.-t) + rad2*rad2*t;
+			rbf->rbfa[n].peak = peak0 * mv * rbf->vtotal *
+						rad0*rad0/rad2;
+			rbf->rbfa[n].crad = ANG2R(sqrt(rad2));
 			ovec_from_pos(v, rbf1j->gx, rbf1j->gy);
 			geodesic(v, v0, v, t, GEOD_REL);
 			pos_from_vec(pos, v);
@@ -354,7 +367,7 @@ advect_rbf(const FVECT invec, int lobe_lim)
 	if (sym < 0)				/* can't interpolate? */
 		return(NULL);
 	if (miga[1] == NULL) {			/* advect along edge? */
-		rbf = e_advect_rbf(miga[0], sivec);
+		rbf = e_advect_rbf(miga[0], sivec, lobe_lim);
 		if (single_plane_incident)
 			rotate_rbf(rbf, invec);
 		else
@@ -388,6 +401,7 @@ tryagain:
 					mtx_ncols(miga[2]); k--; )
 			n += (mtx_coef(miga[2],i,k) > cthresh ||
 				mtx_coef(miga[1],j,k) > cthresh);
+						/* are we over our limit? */
 	if ((lobe_lim > 0) & (n > lobe_lim)) {
 		cthresh = cthresh*2. + 10.*FTINY;
 		goto tryagain;
@@ -418,26 +432,28 @@ tryagain:
 	    for (j = 0; j < mtx_ncols(miga[0]); j++) {
 		const float	ma = mtx_coef(miga[0],i,j);
 		const RBFVAL	*rbf1j;
-		double		rad1j, srad2;
+		double		srad2;
 		if (ma <= cthresh)
 			continue;
 		rbf1j = &miga[0]->rbfv[1]->rbfa[j];
-		rad1j = R2ANG(rbf1j->crad);
-		srad2 = (1.-s)*(1.-t)*rad0i*rad0i + s*(1.-t)*rad1j*rad1j;
+		srad2 = R2ANG(rbf1j->crad);
+		srad2 = (1.-s)*(1.-t)*rad0i*rad0i + s*(1.-t)*srad2*srad2;
 		ovec_from_pos(v1, rbf1j->gx, rbf1j->gy);
 		geodesic(v1, v0, v1, s, GEOD_REL);
 		for (k = 0; k < mtx_ncols(miga[2]); k++) {
 		    float		mb = mtx_coef(miga[1],j,k);
 		    float		mc = mtx_coef(miga[2],i,k);
 		    const RBFVAL	*rbf2k;
-		    double		rad2k;
+		    double		rad2;
 		    int			pos[2];
 		    if ((mb <= cthresh) & (mc <= cthresh))
 			continue;
 		    rbf2k = &miga[2]->rbfv[1]->rbfa[k];
-		    rbf->rbfa[n].peak = w0i * ma * (mb*mbfact + mc*mcfact);
-		    rad2k = R2ANG(rbf2k->crad);
-		    rbf->rbfa[n].crad = ANG2R(sqrt(srad2 + t*rad2k*rad2k));
+		    rad2 = R2ANG(rbf2k->crad);
+		    rad2 = srad2 + t*rad2*rad2;
+		    rbf->rbfa[n].peak = w0i * ma * (mb*mbfact + mc*mcfact) *
+					rad0i*rad0i/rad2;
+		    rbf->rbfa[n].crad = ANG2R(sqrt(rad2));
 		    ovec_from_pos(v2, rbf2k->gx, rbf2k->gy);
 		    geodesic(v2, v1, v2, t, GEOD_REL);
 		    pos_from_vec(pos, v2);