--- ray/src/rt/raytrace.c	2015/05/21 15:28:24	2.67
+++ ray/src/rt/raytrace.c	2016/05/16 17:32:10	2.71
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: raytrace.c,v 2.67 2015/05/21 15:28:24 greg Exp $";
+static const char RCSid[] = "$Id: raytrace.c,v 2.71 2016/05/16 17:32:10 greg Exp $";
 #endif
 /*
  *  raytrace.c - routines for tracing and shading rays.
@@ -51,6 +51,8 @@ rayorigin(		/* start new ray from old one */
 		setcolor(r->rcoef, 1., 1., 1.);
 	} else {
 		rw = intens(rc);
+		if (rw > 1.0)
+			rw = 1.0;		/* avoid calculation growth */
 		if (rc != r->rcoef)
 			copycolor(r->rcoef, rc);
 	}
@@ -108,8 +110,12 @@ rayorigin(		/* start new ray from old one */
 	if (r->crtype & SHADOW)			/* shadow commitment */
 		return(0);
 						/* ambient in photon map? */
-	if (r->crtype & AMBIENT && photonMapping)
-		return(-1);
+	if (ro != NULL && ro->crtype & AMBIENT) {
+		if (causticPhotonMapping)
+			return(-1);
+		if (photonMapping && rt != TRANS)
+			return(-1);
+	}
 	if (maxdepth <= 0 && rc != NULL) {	/* Russian roulette */
 		if (minweight <= 0.0)
 			error(USER, "zero ray weight in Russian roulette");
@@ -193,6 +199,11 @@ raytrans(			/* transmit ray as is */
 }
 
 
+/* Macro for test to see if BSDF material uses proxy */
+#define isBSDFproxy(m)	((m)->otype == MAT_BSDF && (m)->oargs.nsargs && \
+				strcmp((m)->oargs.sarg[0], "0"))
+
+
 int
 rayshade(		/* shade ray r with material mod */
 	RAY  *r,
@@ -201,7 +212,7 @@ rayshade(		/* shade ray r with material mod */
 {
 	OBJREC  *m;
 
-	r->rt = r->rot;			/* set effective ray length */
+	r->rt = r->rot;			/* preset effective ray length */
 	for ( ; mod != OVOID; mod = m->omod) {
 		m = objptr(mod);
 		/****** unnecessary test since modifier() is always called
@@ -212,8 +223,9 @@ rayshade(		/* shade ray r with material mod */
 		******/
 					/* hack for irradiance calculation */
 		if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS)) &&
+				(ofun[m->otype].flags & (T_M|T_X)) &&
 				m->otype != MAT_CLIP &&
-				(ofun[m->otype].flags & (T_M|T_X))) {
+				!isBSDFproxy(m)) {
 			if (irr_ignore(m->otype)) {
 				raytrans(r);
 				return(1);