--- ray/src/cv/bsdfrbf.c	2014/02/18 16:42:16	2.18
+++ ray/src/cv/bsdfrbf.c	2014/03/15 19:47:16	2.21
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrbf.c,v 2.18 2014/02/18 16:42:16 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrbf.c,v 2.21 2014/03/15 19:47:16 greg Exp $";
 #endif
 /*
  * Radial basis function representation for BSDF data.
@@ -32,7 +32,7 @@ static const char RCSid[] = "$Id: bsdfrbf.c,v 2.18 201
 #define RSCA		2.2		/* radius scaling factor (empirical) */
 #endif
 #ifndef SMOOTH_MSE
-#define SMOOTH_MSE	2e-5		/* acceptable mean squared error */
+#define SMOOTH_MSE	5e-5		/* acceptable mean squared error */
 #endif
 #ifndef SMOOTH_MSER
 #define SMOOTH_MSER	0.03		/* acceptable relative MSE */
@@ -41,7 +41,7 @@ static const char RCSid[] = "$Id: bsdfrbf.c,v 2.18 201
 
 #define	RBFALLOCB	10		/* RBF allocation block size */
 
-				/* our loaded grid for this incident angle */
+				/* our loaded grid or comparison DSFs */
 GRIDVAL			dsf_grid[GRIDRES][GRIDRES];
 
 /* Start new DSF input grid */
@@ -72,9 +72,7 @@ add_bsdf_data(double theta_out, double phi_out, double
 	ovec[1] = sin((M_PI/180.)*phi_out) * ovec[2];
 	ovec[2] = sqrt(1. - ovec[2]*ovec[2]);
 
-	if (val <= 0)			/* truncate to zero */
-		val = 0;
-	else if (!isDSF)
+	if (!isDSF)
 		val *= ovec[2];		/* convert from BSDF to DSF */
 
 					/* update BSDF histogram */
@@ -83,8 +81,8 @@ add_bsdf_data(double theta_out, double phi_out, double
 
 	pos_from_vec(pos, ovec);
 
-	dsf_grid[pos[0]][pos[1]].vsum += val;
-	dsf_grid[pos[0]][pos[1]].nval++;
+	dsf_grid[pos[0]][pos[1]].sum.v += val;
+	dsf_grid[pos[0]][pos[1]].sum.n++;
 }
 
 /* Compute minimum BSDF from histogram (does not clear) */
@@ -116,7 +114,7 @@ empty_region(int x0, int x1, int y0, int y1)
 
 	for (x = x0; x < x1; x++)
 	    for (y = y0; y < y1; y++)
-		if (dsf_grid[x][y].nval)
+		if (dsf_grid[x][y].sum.n)
 			return(0);
 	return(1);
 }
@@ -134,8 +132,8 @@ smooth_region(int x0, int x1, int y0, int y1)
 	memset(xvec, 0, sizeof(xvec));
 	for (x = x0; x < x1; x++)
 	    for (y = y0; y < y1; y++)
-		if ((n = dsf_grid[x][y].nval) > 0) {
-			double	z = dsf_grid[x][y].vsum;
+		if ((n = dsf_grid[x][y].sum.n) > 0) {
+			double	z = dsf_grid[x][y].sum.v;
 			rMtx[0][0] += x*x*(double)n;
 			rMtx[0][1] += x*y*(double)n;
 			rMtx[0][2] += x*(double)n;
@@ -158,8 +156,8 @@ smooth_region(int x0, int x1, int y0, int y1)
 	sqerr = 0.0;			/* compute mean squared error */
 	for (x = x0; x < x1; x++)
 	    for (y = y0; y < y1; y++)
-		if ((n = dsf_grid[x][y].nval) > 0) {
-			double	d = A*x + B*y + C - dsf_grid[x][y].vsum/n;
+		if ((n = dsf_grid[x][y].sum.n) > 0) {
+			double	d = A*x + B*y + C - dsf_grid[x][y].sum.v/n;
 			sqerr += n*d*d;
 		}
 	if (sqerr <= nvs*SMOOTH_MSE)	/* below absolute MSE threshold? */
@@ -169,7 +167,7 @@ smooth_region(int x0, int x1, int y0, int y1)
 }
 
 /* Create new lobe based on integrated samples in region */
-static void
+static int
 create_lobe(RBFVAL *rvp, int x0, int x1, int y0, int y1)
 {
 	double	vtot = 0.0;
@@ -179,14 +177,16 @@ create_lobe(RBFVAL *rvp, int x0, int x1, int y0, int y
 					/* compute average for region */
 	for (x = x0; x < x1; x++)
 	    for (y = y0; y < y1; y++) {
-		vtot += dsf_grid[x][y].vsum;
-		nv += dsf_grid[x][y].nval;
+		vtot += dsf_grid[x][y].sum.v;
+		nv += dsf_grid[x][y].sum.n;
 	    }
 	if (!nv) {
 		fprintf(stderr, "%s: internal - missing samples in create_lobe\n",
 				progname);
 		exit(1);
 	}
+	if (vtot <= 0)			/* only create positive lobes */
+		return(0);
 					/* peak value based on integral */
 	vtot *= (x1-x0)*(y1-y0)*(2.*M_PI/GRIDRES/GRIDRES)/(double)nv;
 	rad = (RSCA/(double)GRIDRES)*(x1-x0);
@@ -194,6 +194,7 @@ create_lobe(RBFVAL *rvp, int x0, int x1, int y0, int y
 	rvp->crad = ANG2R(rad);
 	rvp->gx = (x0+x1)>>1;
 	rvp->gy = (y0+y1)>>1;
+	return(1);
 }
 
 /* Recursive function to build radial basis function representation */
@@ -235,15 +236,18 @@ build_rbfrep(RBFVAL **arp, int *np, int x0, int x1, in
 			return(-1);
 	}
 					/* create lobes for leaves */
-	if (!branched[0])
-		create_lobe(*arp+(*np)++, x0, xmid, y0, ymid);
-	if (!branched[1])
-		create_lobe(*arp+(*np)++, xmid, x1, y0, ymid);
-	if (!branched[2])
-		create_lobe(*arp+(*np)++, x0, xmid, ymid, y1);
-	if (!branched[3])
-		create_lobe(*arp+(*np)++, xmid, x1, ymid, y1);
-	nadded += nleaves;
+	if (!branched[0] && create_lobe(*arp+*np, x0, xmid, y0, ymid)) {
+		++(*np); ++nadded;
+	}
+	if (!branched[1] && create_lobe(*arp+*np, xmid, x1, y0, ymid)) {
+		++(*np); ++nadded;
+	}
+	if (!branched[2] && create_lobe(*arp+*np, x0, xmid, ymid, y1)) {
+		++(*np); ++nadded;
+	}
+	if (!branched[3] && create_lobe(*arp+*np, xmid, x1, ymid, y1)) {
+		++(*np); ++nadded;
+	}
 	return(nadded);
 }