--- ray/src/common/modobject.c	2013/03/09 18:53:05	2.13
+++ ray/src/common/modobject.c	2013/12/08 18:59:53	2.14
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: modobject.c,v 2.13 2013/03/09 18:53:05 greg Exp $";
+static const char RCSid[] = "$Id: modobject.c,v 2.14 2013/12/08 18:59:53 greg Exp $";
 #endif
 /*
  *  Routines for tracking object modifiers
@@ -88,6 +88,60 @@ object(				/* get an object number from its name */
 #endif
 
 
+static int
+eqreal(				/* are two real values close enough to equal? */
+	double	d1,
+	double	d2
+)
+{
+	if (d2 != 0.0)
+		d1 = d1/d2 - 1.0;
+	return((-FTINY <= d1) & (d1 <= FTINY));
+}
+
+
+int
+eqobjects(			/* check if two objects are equal */
+	OBJECT	obj1,
+	OBJECT	obj2
+)
+{
+	OBJREC	*op1, *op2;
+	int	i;
+
+	if (obj1 == OVOID)
+		return(obj2 == OVOID);
+	if (obj2 == OVOID)
+		return(0);
+	op1 = objptr(obj1);
+	op2 = objptr(obj2);
+	if (op1->omod != op2->omod)
+		return(0);
+	if (op1->otype != op2->otype)
+		return(0);
+	if (strcmp(op1->oname, op2->oname))
+		return(0);
+	if (op1->oargs.nsargs != op2->oargs.nsargs)
+		return(0);
+	if (op1->oargs.nfargs != op2->oargs.nfargs)
+		return(0);
+#ifdef IARGS
+	if (op1->oargs.niargs != op2->oargs.niargs)
+		return(0);
+	for (i = op1->oargs.niargs; i-- > 0; )
+		if (op1->oargs.iarg[i] != op2->oargs.iarg[i])
+			return(0);
+#endif
+	for (i = op1->oargs.nfargs; i-- > 0; )
+		if (!eqreal(op1->oargs.farg[i], op2->oargs.farg[i]))
+			return(0);
+	for (i = op1->oargs.nsargs; i-- > 0; )
+		if (strcmp(op1->oargs.sarg[i], op2->oargs.sarg[i]))
+			return(0);
+	return(1);
+}
+
+
 void
 insertobject(			/* insert new object into our list */
 	OBJECT  obj
@@ -97,6 +151,8 @@ insertobject(			/* insert new object into our list */
 
 	if (ismodifier(objptr(obj)->otype)) {
 		i = otndx(objptr(obj)->oname, &modtab);
+		if (eqobjects(obj, modtab.htab[i]))
+			return;
 		modtab.htab[i] = obj;
 	}
 #ifdef  GETOBJ