--- ray/src/rt/m_alias.c	2004/01/20 22:16:53	2.4
+++ ray/src/rt/m_alias.c	2018/01/09 05:01:15	2.8
@@ -1,13 +1,15 @@
 #ifndef lint
-static const char RCSid[] = "$Id: m_alias.c,v 2.4 2004/01/20 22:16:53 greg Exp $";
+static const char RCSid[] = "$Id: m_alias.c,v 2.8 2018/01/09 05:01:15 greg Exp $";
 #endif
 /*
  * Handler for modifier alias
  */
 
 #include "copyright.h"
+
 #include "ray.h"
 #include "otypes.h"
+#include "rtotypes.h"
 #include "otspecial.h"
 
 /*
@@ -22,9 +24,10 @@ static const char RCSid[] = "$Id: m_alias.c,v 2.4 2004
  */
 
 int
-m_alias(m, r)			/* transfer shading to alias target */
-OBJREC	*m;
-RAY	*r;
+m_alias(			/* transfer shading to alias target */
+	OBJREC	*m,
+	RAY	*r
+)
 {
 	OBJECT	aobj;
 	OBJREC	*aop;
@@ -36,16 +39,24 @@ RAY	*r;
 					/* else replace alias */
 	if (m->oargs.nsargs != 1)
 		objerror(m, INTERNAL, "bad # string arguments");
-	aobj = lastmod(objndx(m), m->oargs.sarg[0]);
-	if (aobj < 0)
-		objerror(m, USER, "bad reference");
-	aop = objptr(aobj);
+	aop = m;
+	aobj = objndx(aop);
+	do {				/* follow alias trail */
+		if (aop->oargs.nsargs == 1)
+			aobj = lastmod(aobj, aop->oargs.sarg[0]);
+		else
+			aobj = aop->omod;
+		if (aobj < 0)
+			objerror(aop, USER, "bad reference");
+		aop = objptr(aobj);
+	} while (aop->otype == MOD_ALIAS);
+					/* copy struct */
 	arec = *aop;
 					/* irradiance hack */
 	if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS)) &&
 			m->otype != MAT_CLIP &&
 			(ofun[arec.otype].flags & (T_M|T_X))) {
-		if (irr_ignore(arec.otype)) {
+		if (istransp(arec.otype) || isBSDFproxy(m)) {
 			raytrans(r);
 			return(1);
 		}