--- ray/src/gen/mkillum2.c	1991/08/23 12:30:33	1.12
+++ ray/src/gen/mkillum2.c	1991/11/08 13:17:47	1.14
@@ -88,7 +88,7 @@ char  *nm;
 		    h = ilhash(dim, 3) + i;
 		    multisamp(sp, 2, urand(h));
 		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1])/nazi;
+		    r2 = (dim[2] + sp[1] - .5)/nazi;
 		    flatdir(dn, r1, r2);
 		    for (j = 0; j < 3; j++)
 			dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*fa->norm[j];
@@ -166,7 +166,7 @@ char  *nm;
 		    multisamp(sp, 4, urand(ilhash(dim,3)+i));
 					/* random direction */
 		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1])/nazi;
+		    r2 = (dim[2] + sp[1] - .5)/nazi;
 		    rounddir(dir, r1, r2);
 					/* random location */
 		    mkaxes(u, v, dir);		/* yuck! */
@@ -236,7 +236,7 @@ char  *nm;
 		    multisamp(sp, 4, urand(ilhash(dim,3)+i));
 					/* random direction */
 		    r1 = (dim[1] + sp[0])/nalt;
-		    r2 = (dim[2] + sp[1])/nalt;
+		    r2 = (dim[2] + sp[1] - .5)/nazi;
 		    flatdir(dn, r1, r2);
 		    for (j = 0; j < 3; j++)
 			dir[j] = -dn[0]*u[j] - dn[1]*v[j] - dn[2]*co->ad[j];
@@ -291,6 +291,7 @@ register struct rtproc  *rt;
 	if (rt->nrays <= 0)
 		return;
 	bzero(rt->buf+6*rt->nrays, 6*sizeof(float));
+	errno = 0;
 	if ( process(rt->pd, (char *)rt->buf, (char *)rt->buf,
 			3*sizeof(float)*rt->nrays,
 			6*sizeof(float)*(rt->nrays+1)) <