--- ray/src/cv/checkBSDF.c	2021/12/15 02:13:27	2.2
+++ ray/src/cv/checkBSDF.c	2022/01/26 17:30:07	2.6
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: checkBSDF.c,v 2.2 2021/12/15 02:13:27 greg Exp $";
+static const char RCSid[] = "$Id: checkBSDF.c,v 2.6 2022/01/26 17:30:07 greg Exp $";
 #endif
 /*
  *  checkBSDF.c
@@ -29,7 +29,7 @@ typedef struct {
 const SimpleStats	SSinit = {FHUGE, -FHUGE, .0, 0};
 
 				/* relative difference formula */
-#define rdiff(a,b)	((a)>(b) ? ((a)-(b))/(a) : ((b)-(a))/(b))
+#define rdiff(a,b)	((a)>(b) ? ((a)-(b))/((a)+FTINY) : ((b)-(a))/((b)+FTINY))
 
 /* Figure out BSDF type (and optionally determine if in color) */
 const char *
@@ -177,9 +177,15 @@ checkReciprocity(const char *nm, const int side1, cons
 	if (fl & F_MATRIX) {			/* special case for matrix BSDF */
 		const SDMat	*m = (const SDMat *)df->comp[0].dist;
 		int		i = m->ninc;
+		double		diffuseY;
 		FVECT		vin, vout;
 		double		fwdY;
 		SDValue		rev;
+		if (side1 == side2)
+			diffuseY = (side1 > 0) ? bsdf->rLambFront.cieY : bsdf->rLambBack.cieY;
+		else
+			diffuseY = (side1 > 0) ? bsdf->tLambFront.cieY : bsdf->tLambBack.cieY;
+		diffuseY /= M_PI;
 		while (i--) {
 		    int	o = m->nout;
 		    if (!mBSDF_incvec(vin, m, i+.5))
@@ -187,7 +193,7 @@ checkReciprocity(const char *nm, const int side1, cons
 		    while (o--) {
 			if (!mBSDF_outvec(vout, m, o+.5))
 				continue;
-			fwdY = mBSDF_value(m, o, i);
+			fwdY = mBSDF_value(m, o, i) + diffuseY;
 			if (fwdY <= 1e-4)
 				continue;
 			if (SDreportError( SDevalBSDF(&rev, vout, vin, bsdf), stderr))
@@ -196,7 +202,7 @@ checkReciprocity(const char *nm, const int side1, cons
 				addStat(&myStats, rdiff(fwdY, rev.cieY));
 		    }
 		}
-	} if (fl & F_ISOTROPIC) {		/* isotropic case */
+	} else if (fl & F_ISOTROPIC) {		/* isotropic case */
 		const double	stepSize = sqrt(df->minProjSA/M_PI);
 		FVECT		vin;
 		vin[1] = 0;
@@ -230,7 +236,7 @@ checkXML(char *fname)
 	puts("=====================================================");
 	printf("File: '%s'\n", fname);
 	SDclearBSDF(&myBSDF, fname);
-	pth = getpath(fname, getrlibpath(), R_OK);
+	pth = getpath(fname, getrlibpath(), 0);
 	if (!pth) {
 		fprintf(stderr, "Cannot find file '%s'\n", fname);
 		return 0;
@@ -245,13 +251,13 @@ checkXML(char *fname)
 	printf("Color: %d\n", (flags & F_IN_COLOR) != 0);
 	printf("Has Geometry: %d\n", (myBSDF.mgf != NULL));
 	puts("Component\tLambertian XYZ %\tMax. Dir\tMin. Angle");
-	detailComponent("Internal Refl", &myBSDF.rLambFront, myBSDF.rf);
-	detailComponent("External Refl", &myBSDF.rLambBack, myBSDF.rb);
+	detailComponent("Interior Refl", &myBSDF.rLambFront, myBSDF.rf);
+	detailComponent("Exterior Refl", &myBSDF.rLambBack, myBSDF.rb);
 	detailComponent("Int->Ext Trans", &myBSDF.tLambFront, myBSDF.tf);
 	detailComponent("Ext->Int Trans", &myBSDF.tLambBack, myBSDF.tb);
 	puts("Component\tReciprocity Error (min avg max %)");
-	checkReciprocity("Front Refl", 1, 1, &myBSDF, flags);
-	checkReciprocity("Back Refl", -1, -1, &myBSDF, flags);
+	checkReciprocity("Interior Refl", 1, 1, &myBSDF, flags);
+	checkReciprocity("Exterior Refl", -1, -1, &myBSDF, flags);
 	checkReciprocity("Transmission", -1, 1, &myBSDF, flags);
 	SDfreeBSDF(&myBSDF);
 	return 1;