--- ray/src/rt/normal.c	1992/05/15 13:07:55	2.18
+++ ray/src/rt/normal.c	1992/05/19 17:09:03	2.20
@@ -135,7 +135,7 @@ double  omega;			/* light source size */
 		 *  is always modified by material color.
 		 */
 						/* roughness + source */
-		dtmp = np->alpha2/4.0 + omega/PI;
+		dtmp = np->alpha2 + omega/PI;
 						/* gaussian */
 		dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(4.*PI*dtmp);
 						/* worth using? */
@@ -240,8 +240,7 @@ register RAY  *r;
 				transtest = 2;
 			} else {
 				for (i = 0; i < 3; i++)		/* perturb */
-					nd.prdir[i] = r->rdir[i] -
-							0.5*r->pert[i];
+					nd.prdir[i] = r->rdir[i] - r->pert[i];
 				if (DOT(nd.prdir, r->ron) < -FTINY)
 					normalize(nd.prdir);	/* OK */
 				else
@@ -370,7 +369,7 @@ register NORMDAT  *np;
 		if (rv[1] <= FTINY)
 			d = 1.0;
 		else
-			d = sqrt( np->alpha2/4.0 * -log(rv[1]) );
+			d = sqrt( -log(rv[1]) * np->alpha2 );
 		for (i = 0; i < 3; i++)
 			sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]);
 		if (DOT(sr.rdir, r->ron) < -FTINY)