--- ray/src/rt/ambient.h	1991/06/07 10:03:51	1.1
+++ ray/src/rt/ambient.h	1991/08/20 10:02:43	1.2
@@ -35,3 +35,5 @@ extern double  maxarad;		/* maximum ambient radius */
 extern double  minarad;		/* minimum ambient radius */
 
 extern double  sumambient(), doambient(), makeambient();
+
+#define  AVGREFL	0.5	/* assumed average reflectance */