--- ray/src/rt/ambcomp.c	1992/10/02 16:14:38	2.4
+++ ray/src/rt/ambcomp.c	1996/04/23 11:06:54	2.6
@@ -139,14 +139,15 @@ FVECT  pg, dg;
 			dp->n = 0;
 			if (divsample(dp, &hemi, r) < 0)
 				goto oopsy;
+			arad += dp->r;
 			if (div != NULL)
 				dp++;
-			else {
+			else
 				addcolor(acol, dp->v);
-				arad += dp->r;
-			}
 		}
-	if (ns > 0) {			/* perform super-sampling */
+	if (ns > 0 && arad > FTINY && ndivs/arad < minarad)
+		ns = 0;			/* close enough */
+	else if (ns > 0) {		/* else perform super-sampling */
 		comperrs(div, &hemi);			/* compute errors */
 		qsort(div, ndivs, sizeof(AMBSAMP), ambcmp);	/* sort divs */
 						/* super-sample */
@@ -168,6 +169,7 @@ FVECT  pg, dg;
 	}
 					/* compute returned values */
 	if (div != NULL) {
+		arad = 0.0;
 		for (i = ndivs, dp = div; i-- > 0; dp++) {
 			arad += dp->r;
 			if (dp->n > 1) {