--- ray/src/rt/rview.c	1994/09/14 18:35:21	2.13
+++ ray/src/rt/rview.c	1994/12/21 09:52:07	2.14
@@ -41,6 +41,8 @@ double	srcsizerat = 0.;		/* maximum ratio source size/
 double	specthresh = .3;		/* specular sampling threshold */
 double	specjitter = 1.;		/* specular sampling jitter */
 
+int  backvis = 1;			/* back face visibility */
+
 int  maxdepth = 4;			/* maximum recursion depth */
 double	minweight = 1e-2;		/* minimum ray weight */