--- ray/src/rt/ambcomp.c	1991/06/13 10:54:00	1.6
+++ ray/src/rt/ambcomp.c	1991/06/13 13:58:24	1.8
@@ -86,7 +86,7 @@ RAY  *r;
 	rayvalue(&ar);
 	ndims--;
 	addcolor(dp->v, ar.rcol);
-	if (ar.rt < FHUGE)
+	if (ar.rt > FTINY && ar.rt < FHUGE)
 		dp->r += 1.0/ar.rt;
 					/* (re)initialize error */
 	if (dp->n++) {
@@ -213,6 +213,14 @@ FVECT  pg, dg;
 	else if (arad < minarad)
 		arad = minarad;
 	arad /= sqrt(r->rweight);
+	if (pg != NULL) {		/* clip pos. gradient if too large */
+		d = 4.0*DOT(pg,pg)*arad*arad;
+		if (d > 1.0) {
+			d = 1.0/sqrt(d);
+			for (i = 0; i < 3; i++)
+				pg[i] *= d;
+		}
+	}
 	return(arad);
 oopsy:
 	if (div != NULL)