--- ray/src/rt/aniso.c	1994/12/21 09:51:44	2.28
+++ ray/src/rt/aniso.c	1995/09/15 15:47:32	2.29
@@ -263,8 +263,7 @@ register RAY  *r;
 						/* diffuse reflection */
 	nd.rdiff = 1.0 - nd.trans - nd.rspec;
 
-	if (r->ro != NULL && (r->ro->otype == OBJ_FACE ||
-			r->ro->otype == OBJ_RING))
+	if (r->ro != NULL && isflat(r->ro->otype))
 		nd.specfl |= SP_FLAT;
 
 	getacoords(r, &nd);			/* set up coordinates */