--- ray/src/gen/mkillum.h	1991/07/24 16:48:25	1.3
+++ ray/src/gen/mkillum.h	1991/08/23 12:30:31	1.5
@@ -26,7 +26,8 @@ struct illum_args {
 	char	altmat[MAXSTR];		/* alternate material name */
 	int	sampdens;		/* point sample density */
 	int	nsamps;			/* # of samples in each direction */
-	float	col[3];			/* average color */
+	float	minbrt;			/* minimum average brightness */
+	float	col[3];			/* computed average color */
 };				/* illum options */
 
 struct rtproc {