--- ray/src/common/bsdf_t.c	2013/07/04 15:14:45	3.30
+++ ray/src/common/bsdf_t.c	2014/03/17 01:53:51	3.32
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdf_t.c,v 3.30 2013/07/04 15:14:45 greg Exp $";
+static const char RCSid[] = "$Id: bsdf_t.c,v 3.32 2014/03/17 01:53:51 greg Exp $";
 #endif
 /*
  *  bsdf_t.c
@@ -284,7 +284,7 @@ SDdotravTre(const SDNode *st, const double *pos, int c
 		unsigned	skipmask = 0;
 		csiz *= .5;
 		for (i = st->ndim; i--; )
-			if (1<<i & cmask)
+			if (1<<i & cmask) {
 				if (pos[i] < cmin[i] + csiz)
 					for (n = 1 << st->ndim; n--; ) {
 						if (n & 1<<i)
@@ -295,6 +295,7 @@ SDdotravTre(const SDNode *st, const double *pos, int c
 						if (!(n & 1<<i))
 							skipmask |= 1<<n;
 					}
+			}
 		for (n = 1 << st->ndim; n--; ) {
 			if (1<<n & skipmask)
 				continue;
@@ -468,7 +469,8 @@ SDqueryTre(const SDTre *sdt, const FVECT outVec, const
 					/* convert vector coordinates */
 	if (sdt->st->ndim == 3) {
 		spinvector(rOutVec, outVec, zvec, -atan2(-inVec[1],-inVec[0]));
-		gridPos[0] = .5 - .5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
+		gridPos[0] = (.5-FTINY) -
+				.5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
 		SDdisk2square(gridPos+1, rOutVec[0], rOutVec[1]);
 	} else if (sdt->st->ndim == 4) {
 		SDdisk2square(gridPos, -inVec[0], -inVec[1]);
@@ -672,7 +674,8 @@ SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
 	if (sdt->st->ndim == 3) {	/* isotropic BSDF? */
 		if (mode != sdt->sidef)	/* XXX unhandled reciprocity */
 			return &SDemptyCD;
-		inCoord[0] = .5 - .5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
+		inCoord[0] = (.5-FTINY) -
+				.5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
 	} else if (sdt->st->ndim == 4) {
 		if (mode != sdt->sidef)	/* use reciprocity? */
 			SDdisk2square(inCoord, inVec[0], inVec[1]);
@@ -797,8 +800,7 @@ SDsampTreCDist(FVECT ioVec, double randX, const SDCDst
 	SDsquare2disk(gpos, gpos[0], gpos[1]);
 					/* compute Z-coordinate */
 	gpos[2] = 1. - gpos[0]*gpos[0] - gpos[1]*gpos[1];
-	if (gpos[2] > 0)		/* paranoia, I hope */
-		gpos[2] = sqrt(gpos[2]);
+	gpos[2] = sqrt(gpos[2]*(gpos[2]>0));
 					/* emit from back? */
 	if ((cd->sidef == SD_BREFL) | (cd->sidef == SD_FXMIT))
 		gpos[2] = -gpos[2];