--- ray/src/rt/aniso.c	1992/01/14 16:16:48	2.4
+++ ray/src/rt/aniso.c	1992/03/03 16:20:00	2.11
@@ -39,11 +39,10 @@ extern double  specjitter;		/* specular sampling jitte
 				/* specularity flags */
 #define  SP_REFL	01		/* has reflected specular component */
 #define  SP_TRAN	02		/* has transmitted specular */
-#define  SP_PURE	010		/* purely specular (zero roughness) */
-#define  SP_FLAT	020		/* reflecting surface is flat */
-#define  SP_RBLT	040		/* reflection below sample threshold */
-#define  SP_TBLT	0100		/* transmission below threshold */
-#define  SP_BADU	0200		/* bad u direction calculation */
+#define  SP_FLAT	04		/* reflecting surface is flat */
+#define  SP_RBLT	010		/* reflection below sample threshold */
+#define  SP_TBLT	020		/* transmission below threshold */
+#define  SP_BADU	040		/* bad u direction calculation */
 
 typedef struct {
 	OBJREC  *mp;		/* material pointer */
@@ -51,6 +50,7 @@ typedef struct {
 	short  specfl;		/* specularity flags, defined above */
 	COLOR  mcolor;		/* color of this material */
 	COLOR  scolor;		/* color of specular component */
+	FVECT  vrefl;		/* vector in reflected direction */
 	FVECT  prdir;		/* vector in transmitted direction */
 	FVECT  u, v;		/* u and v vectors orienting anisotropy */
 	double  u_alpha;	/* u roughness */
@@ -93,7 +93,7 @@ double  omega;			/* light source size */
 		scalecolor(ctmp, dtmp);
 		addcolor(cval, ctmp);
 	}
-	if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE|SP_BADU)) == SP_REFL) {
+	if (ldot > FTINY && (np->specfl&(SP_REFL|SP_BADU)) == SP_REFL) {
 		/*
 		 *  Compute specular reflection coefficient using
 		 *  anisotropic gaussian distribution model.
@@ -135,7 +135,7 @@ double  omega;			/* light source size */
 		scalecolor(ctmp, dtmp);
 		addcolor(cval, ctmp);
 	}
-	if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE|SP_BADU)) == SP_TRAN) {
+	if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_BADU)) == SP_TRAN) {
 		/*
 		 *  Compute specular transmission.  Specular transmission
 		 *  is always modified by material color.
@@ -159,12 +159,11 @@ register OBJREC  *m;
 register RAY  *r;
 {
 	ANISODAT  nd;
-	double  transtest, transdist;
 	double  dtmp;
 	COLOR  ctmp;
 	register int  i;
 						/* easy shadow test */
-	if (r->crtype & SHADOW && m->otype != MAT_TRANS2)
+	if (r->crtype & SHADOW)
 		return;
 
 	if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6))
@@ -179,8 +178,8 @@ register RAY  *r;
 	nd.specfl = 0;
 	nd.u_alpha = m->oargs.farg[4];
 	nd.v_alpha = m->oargs.farg[5];
-	if (nd.u_alpha <= FTINY || nd.v_alpha <= FTINY)
-		nd.specfl |= SP_PURE;
+	if (nd.u_alpha < 1e-6 || nd.v_alpha <= 1e-6)
+		objerror(m, USER, "roughness too small");
 						/* reorient if necessary */
 	if (r->rod < 0.0)
 		flipsurface(r);
@@ -190,7 +189,6 @@ register RAY  *r;
 	if (nd.pdot < .001)
 		nd.pdot = .001;			/* non-zero for diraniso() */
 	multcolor(nd.mcolor, r->pcol);		/* modify material color */
-	transtest = 0;
 						/* get specular component */
 	if ((nd.rspec = m->oargs.farg[3]) > FTINY) {
 		nd.specfl |= SP_REFL;
@@ -206,20 +204,16 @@ register RAY  *r;
 			colval(nd.scolor,i) += (1.0-colval(nd.scolor,i))*dtmp;
 		nd.rspec += (1.0-nd.rspec)*dtmp;
 						/* check threshold */
-		if (nd.rspec <= specthresh+FTINY)
+		if (specthresh > FTINY &&
+				((specthresh >= 1.-FTINY ||
+				specthresh + (.05 - .1*frandom()) > nd.rspec)))
 			nd.specfl |= SP_RBLT;
-
-		if (!(r->crtype & SHADOW) && nd.specfl & SP_PURE) {
-			RAY  lr;
-			if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) {
-				for (i = 0; i < 3; i++)
-					lr.rdir[i] = r->rdir[i] +
-						2.0*nd.pdot*nd.pnorm[i];
-				rayvalue(&lr);
-				multcolor(lr.rcol, nd.scolor);
-				addcolor(r->rcol, lr.rcol);
-			}
-		}
+						/* compute refl. direction */
+		for (i = 0; i < 3; i++)
+			nd.vrefl[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i];
+		if (DOT(nd.vrefl, r->ron) <= FTINY)	/* penetration? */
+			for (i = 0; i < 3; i++)		/* safety measure */
+				nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
 	}
 						/* compute transmission */
 	if (m->otype == MAT_TRANS) {
@@ -229,49 +223,36 @@ register RAY  *r;
 		if (nd.tspec > FTINY) {
 			nd.specfl |= SP_TRAN;
 							/* check threshold */
-			if (nd.tspec <= specthresh+FTINY)
+			if (specthresh > FTINY &&
+					((specthresh >= 1.-FTINY ||
+					specthresh +
+					    (.05 - .1*frandom()) > nd.tspec)))
 				nd.specfl |= SP_TBLT;
-			if (r->crtype & SHADOW ||
-					DOT(r->pert,r->pert) <= FTINY*FTINY) {
+			if (DOT(r->pert,r->pert) <= FTINY*FTINY) {
 				VCOPY(nd.prdir, r->rdir);
-				transtest = 2;
 			} else {
 				for (i = 0; i < 3; i++)		/* perturb */
 					nd.prdir[i] = r->rdir[i] -
-							.75*r->pert[i];
-				normalize(nd.prdir);
+							0.5*r->pert[i];
+				if (DOT(nd.prdir, r->ron) < -FTINY)
+					normalize(nd.prdir);	/* OK */
+				else
+					VCOPY(nd.prdir, r->rdir);
 			}
 		}
 	} else
 		nd.tdiff = nd.tspec = nd.trans = 0.0;
-						/* transmitted ray */
-	if ((nd.specfl&(SP_TRAN|SP_PURE)) == (SP_TRAN|SP_PURE)) {
-		RAY  lr;
-		if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) {
-			VCOPY(lr.rdir, nd.prdir);
-			rayvalue(&lr);
-			scalecolor(lr.rcol, nd.tspec);
-			multcolor(lr.rcol, nd.mcolor);	/* modified by color */
-			addcolor(r->rcol, lr.rcol);
-			transtest *= bright(lr.rcol);
-			transdist = r->rot + lr.rt;
-		}
-	}
 
-	if (r->crtype & SHADOW)			/* the rest is shadow */
-		return;
 						/* diffuse reflection */
 	nd.rdiff = 1.0 - nd.trans - nd.rspec;
 
-	if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY)
-		return;				/* 100% pure specular */
-
-	if (r->ro->otype == OBJ_FACE || r->ro->otype == OBJ_RING)
+	if (r->ro != NULL && (r->ro->otype == OBJ_FACE ||
+			r->ro->otype == OBJ_RING))
 		nd.specfl |= SP_FLAT;
 
 	getacoords(r, &nd);			/* set up coordinates */
 
-	if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & (SP_PURE|SP_BADU)))
+	if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & SP_BADU))
 		agaussamp(r, &nd);
 
 	if (nd.rdiff > FTINY) {		/* ambient from this side */
@@ -296,9 +277,6 @@ register RAY  *r;
 	}
 					/* add direct component */
 	direct(r, diraniso, &nd);
-					/* check distance */
-	if (transtest > bright(r->rcol))
-		r->rt = transdist;
 }
 
 
@@ -340,43 +318,66 @@ register ANISODAT  *np;
 	FVECT  h;
 	double  rv[2];
 	double  d, sinp, cosp;
-	int  ntries;
 	register int  i;
 					/* compute reflection */
 	if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL &&
 			rayorigin(&sr, r, SPECULAR, np->rspec) == 0) {
 		dimlist[ndims++] = (int)np->mp;
-		for (ntries = 0; ntries < 10; ntries++) {
-			dimlist[ndims] = ntries * 3601;
-			d = urand(ilhash(dimlist,ndims+1)+samplendx);
-			multisamp(rv, 2, d);
-			d = 2.0*PI * rv[0];
-			cosp = np->u_alpha * cos(d);
-			sinp = np->v_alpha * sin(d);
-			d = sqrt(cosp*cosp + sinp*sinp);
-			cosp /= d;
-			sinp /= d;
-			rv[1] = 1.0 - specjitter*rv[1];
-			if (rv[1] <= FTINY)
-				d = 1.0;
-			else
-				d = sqrt(-log(rv[1]) /
-					(cosp*cosp/(np->u_alpha*np->u_alpha) +
-					 sinp*sinp/(np->v_alpha*np->v_alpha)));
-			for (i = 0; i < 3; i++)
-				h[i] = np->pnorm[i] +
-					d*(cosp*np->u[i] + sinp*np->v[i]);
-			d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d);
-			for (i = 0; i < 3; i++)
-				sr.rdir[i] = r->rdir[i] + d*h[i];
-			if (DOT(sr.rdir, r->ron) > FTINY) {
-				rayvalue(&sr);
-				multcolor(sr.rcol, np->scolor);
-				addcolor(r->rcol, sr.rcol);
-				break;
-			}
-		}
+		d = urand(ilhash(dimlist,ndims)+samplendx);
+		multisamp(rv, 2, d);
+		d = 2.0*PI * rv[0];
+		cosp = np->u_alpha * cos(d);
+		sinp = np->v_alpha * sin(d);
+		d = sqrt(cosp*cosp + sinp*sinp);
+		cosp /= d;
+		sinp /= d;
+		rv[1] = 1.0 - specjitter*rv[1];
+		if (rv[1] <= FTINY)
+			d = 1.0;
+		else
+			d = sqrt(-log(rv[1]) /
+				(cosp*cosp/(np->u_alpha*np->u_alpha) +
+				 sinp*sinp/(np->v_alpha*np->v_alpha)));
+		for (i = 0; i < 3; i++)
+			h[i] = np->pnorm[i] +
+				d*(cosp*np->u[i] + sinp*np->v[i]);
+		d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d);
+		for (i = 0; i < 3; i++)
+			sr.rdir[i] = r->rdir[i] + d*h[i];
+		if (DOT(sr.rdir, r->ron) <= FTINY)	/* penetration? */
+			VCOPY(sr.rdir, np->vrefl);	/* jitter no good */
+		rayvalue(&sr);
+		multcolor(sr.rcol, np->scolor);
+		addcolor(r->rcol, sr.rcol);
 		ndims--;
 	}
 					/* compute transmission */
+	if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN &&
+			rayorigin(&sr, r, SPECULAR, np->tspec) == 0) {
+		dimlist[ndims++] = (int)np->mp;
+		d = urand(ilhash(dimlist,ndims)+1823+samplendx);
+		multisamp(rv, 2, d);
+		d = 2.0*PI * rv[0];
+		cosp = cos(d);
+		sinp = sin(d);
+		rv[1] = 1.0 - specjitter*rv[1];
+		if (rv[1] <= FTINY)
+			d = 1.0;
+		else
+			d = sqrt(-log(rv[1]) /
+				(cosp*cosp*4./(np->u_alpha*np->u_alpha) +
+				 sinp*sinp*4./(np->v_alpha*np->v_alpha)));
+		for (i = 0; i < 3; i++)
+			sr.rdir[i] = np->prdir[i] +
+					d*(cosp*np->u[i] + sinp*np->v[i]);
+		if (DOT(sr.rdir, r->ron) < -FTINY)
+			normalize(sr.rdir);		/* OK, normalize */
+		else
+			VCOPY(sr.rdir, np->prdir);	/* else no jitter */
+		rayvalue(&sr);
+		scalecolor(sr.rcol, np->tspec);
+		multcolor(sr.rcol, np->mcolor);		/* modify by color */
+		addcolor(r->rcol, sr.rcol);
+		ndims--;
+	}
 }