--- ray/src/rt/virtuals.c	1991/07/30 18:23:45	1.19
+++ ray/src/rt/virtuals.c	1991/08/26 10:10:43	1.26
@@ -19,8 +19,8 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  "random.h"
 
-#define  MINSAMPLES	5		/* minimum number of pretest samples */
-#define  STESTMAX	30		/* maximum seeks per sample */
+#define  MINSAMPLES	16		/* minimum number of pretest samples */
+#define  STESTMAX	32		/* maximum seeks per sample */
 
 
 double  getdisk();
@@ -44,8 +44,10 @@ markvirtuals()			/* find and mark virtual sources */
 		if (!isvlight(objptr(o->omod)->otype))
 			continue;
 		if (sfun[o->otype].of == NULL ||
-				sfun[o->otype].of->getpleq == NULL)
-			objerror(o, USER, "illegal material");
+				sfun[o->otype].of->getpleq == NULL) {
+			objerror(o,WARNING,"secondary sources not supported");
+			continue;
+		}
 		if (nvobjects == 0)
 			vobject = (OBJECT *)malloc(sizeof(OBJECT));
 		else
@@ -199,7 +201,7 @@ MAT4  pm;
 		if (source[sn].sflags & SFLAT) {	/* behind source? */
 			multv3(nsnorm, source[sn].snorm, pm);
 			normalize(nsnorm);
-			if (!checkspot(&ourspot, nsnorm))
+			if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm))
 				return(-1);
 		}
 	}
@@ -285,13 +287,17 @@ register int  sn;	/* target source number */
 	getplaneq(onorm, o);
 				/* set number of rays to sample */
 	if (source[sn].sflags & SDISTANT) {
-		n = (2./3.*PI*PI)*or2/(thescene.cusize*thescene.cusize)*
-				vspretest + .5;
+					/* 32. == heuristic constant */
+		n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5;
 		infront = DOT(onorm, source[sn].sloc) > 0.;
 	} else {
 		for (i = 0; i < 3; i++)
 			offsdir[i] = source[sn].sloc[i] - oc[i];
-		n = or2/DOT(offsdir,offsdir)*vspretest + .5;
+		d = DOT(offsdir,offsdir);
+		if (d <= FTINY)
+			n = 2.*PI * vspretest + .5;
+		else
+			n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5;
 		infront = DOT(onorm, offsdir) > 0.;
 	}
 	if (n < MINSAMPLES) n = MINSAMPLES;
@@ -313,9 +319,9 @@ register int  sn;	/* target source number */
 #endif
 				return(f);	/* too small a target! */
 			}
+			multisamp(offsdir, 3, urand(sn*931+5827+ssn));
 			for (i = 0; i < 3; i++)
-				offsdir[i] = or*(1. -
-					2.*urand(urind(931*i+5827,ssn)));
+				offsdir[i] = or*(1. - 2.*offsdir[i]);
 			ssn++;
 			for (i = 0; i < 3; i++)
 				sr.rorg[i] = oc[i] + offsdir[i];
@@ -343,9 +349,7 @@ register int  sn;	/* target source number */
 		nok++;
 					/* check against obstructions */
 		rayclear(&sr);
-		sr.revf = raytrace;
-		rayvalue(&sr);
-		if (bright(sr.rcol) > FTINY)
+		if (!localhit(&sr, &thescene) || sr.ro == source[sn].so)
 			nhit++;
 		if (nhit > 0 && nhit < nok) {
 #ifdef DEBUG