--- ray/src/cv/mgf2rad.c	1994/07/01 10:20:19	2.5
+++ ray/src/cv/mgf2rad.c	1996/07/24 13:07:48	2.23
@@ -1,4 +1,4 @@
-/* Copyright (c) 1994 Regents of the University of California */
+/* Copyright (c) 1996 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -17,10 +17,14 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #define putv(v)		printf("%18.12g %18.12g %18.12g\n",(v)[0],(v)[1],(v)[2])
 
+#define invert		(xf_context != NULL && xf_context->rev)
+
 double	glowdist = FHUGE;		/* glow test distance */
 
-double  emult = 1.;			/* emmitter multiplier */
+double  emult = 1.;			/* emitter multiplier */
 
+FILE	*matfp = stdout;		/* material output file */
+
 int	r_comment(), r_cone(), r_cyl(), r_face(), r_ies(), r_ring(), r_sph();
 char	*material(), *object(), *addarg();
 
@@ -29,66 +33,87 @@ main(argc, argv)		/* convert files to stdout */
 int	argc;
 char	*argv[];
 {
-	int	i, rv;
+	int	i;
+				/* print out parser version */
+	printf("## Translated from MGF Version %d.%d\n", MG_VMAJOR, MG_VMINOR);
 				/* initialize dispatch table */
-	mg_ehand[MG_E_COMMENT] = r_comment;
-	mg_ehand[MG_E_COLOR] = c_hcolor;
-	mg_ehand[MG_E_CONE] = r_cone;
-	mg_ehand[MG_E_CMIX] = c_hcolor;
-	mg_ehand[MG_E_CSPEC] = c_hcolor;
-	mg_ehand[MG_E_CXY] = c_hcolor;
-	mg_ehand[MG_E_CYL] = r_cyl;
-	mg_ehand[MG_E_ED] = c_hmaterial;
-	mg_ehand[MG_E_FACE] = r_face;
-	mg_ehand[MG_E_IES] = r_ies;
-	mg_ehand[MG_E_MATERIAL] = c_hmaterial;
-	mg_ehand[MG_E_NORMAL] = c_hvertex;
-	mg_ehand[MG_E_OBJECT] = obj_handler;
-	mg_ehand[MG_E_POINT] = c_hvertex;
-	mg_ehand[MG_E_RD] = c_hmaterial;
-	mg_ehand[MG_E_RING] = r_ring;
-	mg_ehand[MG_E_RS] = c_hmaterial;
-	mg_ehand[MG_E_SPH] = r_sph;
-	mg_ehand[MG_E_TD] = c_hmaterial;
-	mg_ehand[MG_E_TS] = c_hmaterial;
-	mg_ehand[MG_E_VERTEX] = c_hvertex;
-	mg_ehand[MG_E_XF] = xf_handler;
+	mg_ehand[MG_E_COMMENT] = r_comment;	/* we pass comments */
+	mg_ehand[MG_E_COLOR] = c_hcolor;	/* they get color */
+	mg_ehand[MG_E_CONE] = r_cone;		/* we do cones */
+	mg_ehand[MG_E_CMIX] = c_hcolor;		/* they mix colors */
+	mg_ehand[MG_E_CSPEC] = c_hcolor;	/* they get spectra */
+	mg_ehand[MG_E_CXY] = c_hcolor;		/* they get chromaticities */
+	mg_ehand[MG_E_CCT] = c_hcolor;		/* they get color temp's */
+	mg_ehand[MG_E_CYL] = r_cyl;		/* we do cylinders */
+	mg_ehand[MG_E_ED] = c_hmaterial;	/* they get emission */
+	mg_ehand[MG_E_FACE] = r_face;		/* we do faces */
+	mg_ehand[MG_E_IES] = r_ies;		/* we do IES files */
+	mg_ehand[MG_E_IR] = c_hmaterial;	/* they get refractive index */
+	mg_ehand[MG_E_MATERIAL] = c_hmaterial;	/* they get materials */
+	mg_ehand[MG_E_NORMAL] = c_hvertex;	/* they get normals */
+	mg_ehand[MG_E_OBJECT] = obj_handler;	/* they track object names */
+	mg_ehand[MG_E_POINT] = c_hvertex;	/* they get points */
+	mg_ehand[MG_E_RD] = c_hmaterial;	/* they get diffuse refl. */
+	mg_ehand[MG_E_RING] = r_ring;		/* we do rings */
+	mg_ehand[MG_E_RS] = c_hmaterial;	/* they get specular refl. */
+	mg_ehand[MG_E_SIDES] = c_hmaterial;	/* they get # sides */
+	mg_ehand[MG_E_SPH] = r_sph;		/* we do spheres */
+	mg_ehand[MG_E_TD] = c_hmaterial;	/* they get diffuse trans. */
+	mg_ehand[MG_E_TS] = c_hmaterial;	/* they get specular trans. */
+	mg_ehand[MG_E_VERTEX] = c_hvertex;	/* they get vertices */
+	mg_ehand[MG_E_XF] = xf_handler;		/* they track transforms */
 	mg_init();		/* initialize the parser */
-					/* get options & print header */
+					/* get our options & print header */
 	printf("## %s", argv[0]);
 	for (i = 1; i < argc && argv[i][0] == '-'; i++) {
 		printf(" %s", argv[i]);
 		switch (argv[i][1]) {
 		case 'g':			/* glow distance (meters) */
-			if (argv[i][2] || badarg(argc-i, argv+i, "f"))
+			if (argv[i][2] || badarg(argc-i-1, argv+i+1, "f"))
 				goto userr;
 			glowdist = atof(argv[++i]);
 			printf(" %s", argv[i]);
 			break;
 		case 'e':			/* emitter multiplier */
-			if (argv[i][2] || badarg(argc-i, argv+i, "f"))
+			if (argv[i][2] || badarg(argc-i-1, argv+i+1, "f"))
 				goto userr;
 			emult = atof(argv[++i]);
 			printf(" %s", argv[i]);
 			break;
+		case 'm':			/* materials file */
+			matfp = fopen(argv[++i], "a");
+			if (matfp == NULL) {
+				fprintf(stderr, "%s: cannot append\n", argv[i]);
+				exit(1);
+			}
+			printf(" %s", argv[i]);
+			break;
 		default:
 			goto userr;
 		}
 	}
 	putchar('\n');
 	if (i == argc) {		/* convert stdin */
-		if ((rv = mg_load(NULL)) != MG_OK)
+		if (mg_load(NULL) != MG_OK)
 			exit(1);
+		if (mg_nunknown)
+			printf("## %s: %u unknown entities\n",
+					argv[0], mg_nunknown);
 	} else				/* convert each file */
 		for ( ; i < argc; i++) {
 			printf("## %s %s ##############################\n",
 					argv[0], argv[i]);
-			if ((rv = mg_load(argv[i])) != MG_OK)
+			if (mg_load(argv[i]) != MG_OK)
 				exit(1);
+			if (mg_nunknown) {
+				printf("## %s %s: %u unknown entities\n",
+						argv[0], argv[i], mg_nunknown);
+				mg_nunknown = 0;
+			}
 		}
 	exit(0);
 userr:
-	fprintf(stderr, "Usage: %s [-g dist][-m mult] [file.mgf] ..\n",
+	fprintf(stderr, "Usage: %s [-g dist][-e mult][-m matf] [file.mgf] ..\n",
 			argv[0]);
 	exit(1);
 }
@@ -99,8 +124,8 @@ r_comment(ac, av)		/* repeat a comment verbatim */
 register int	ac;
 register char	**av;
 {
-	fputs("\n#", stdout);	/* use Radiance comment character */
-	while (--ac) {
+	putchar('#');		/* use Radiance comment character */
+	while (--ac) {			/* pass through verbatim */
 		putchar(' ');
 		fputs(*++av, stdout);
 	}
@@ -120,20 +145,21 @@ char	**av;
 	C_VERTEX	*cv1, *cv2;
 	FVECT	p1, p2;
 	int	inv;
-
+					/* check argument count and type */
 	if (ac != 5)
 		return(MG_EARGC);
 	if (!isflt(av[2]) || !isflt(av[4]))
 		return(MG_ETYPE);
+					/* get the endpoint vertices */
 	if ((cv1 = c_getvert(av[1])) == NULL ||
 			(cv2 = c_getvert(av[3])) == NULL)
 		return(MG_EUNDEF);
-	xf_xfmpoint(p1, cv1->p);
+	xf_xfmpoint(p1, cv1->p);	/* transform endpoints */
 	xf_xfmpoint(p2, cv2->p);
-	r1 = xf_scale(atof(av[2]));
+	r1 = xf_scale(atof(av[2]));	/* scale radii */
 	r2 = xf_scale(atof(av[4]));
-	inv = r1 < 0.;
-	if (r1 == 0.) {
+	inv = r1 < 0.;			/* check for inverted cone */
+	if (r1 == 0.) {			/* check for illegal radii */
 		if (r2 == 0.)
 			return(MG_EILL);
 		inv = r2 < 0.;
@@ -143,8 +169,9 @@ char	**av;
 		r1 = -r1;
 		r2 = -r2;
 	}
-	if ((mat = material()) == NULL)
+	if ((mat = material()) == NULL)	/* get material */
 		return(MG_EBADMAT);
+					/* spit the sucker out */
 	printf("\n%s %s %sc%d\n", mat, inv ? "cup" : "cone",
 			object(), ++ncones);
 	printf("0\n0\n8\n");
@@ -166,21 +193,23 @@ char	**av;
 	C_VERTEX	*cv1, *cv2;
 	FVECT	p1, p2;
 	int	inv;
-
+					/* check argument count and type */
 	if (ac != 4)
 		return(MG_EARGC);
 	if (!isflt(av[2]))
 		return(MG_ETYPE);
+					/* get the endpoint vertices */
 	if ((cv1 = c_getvert(av[1])) == NULL ||
 			(cv2 = c_getvert(av[3])) == NULL)
 		return(MG_EUNDEF);
-	xf_xfmpoint(p1, cv1->p);
+	xf_xfmpoint(p1, cv1->p);	/* transform endpoints */
 	xf_xfmpoint(p2, cv2->p);
-	rad = xf_scale(atof(av[2]));
-	if ((inv = rad < 0.))
+	rad = xf_scale(atof(av[2]));	/* scale radius */
+	if ((inv = rad < 0.))		/* check for inverted cylinder */
 		rad = -rad;
-	if ((mat = material()) == NULL)
+	if ((mat = material()) == NULL)	/* get material */
 		return(MG_EBADMAT);
+					/* spit out the primitive */
 	printf("\n%s %s %scy%d\n", mat, inv ? "tube" : "cylinder",
 			object(), ++ncyls);
 	printf("0\n0\n7\n");
@@ -202,19 +231,20 @@ char	**av;
 	C_VERTEX	*cv;
 	FVECT	cent;
 	int	inv;
-
+					/* check argument count and type */
 	if (ac != 3)
 		return(MG_EARGC);
 	if (!isflt(av[2]))
 		return(MG_ETYPE);
-	if ((cv = c_getvert(av[1])) == NULL)
+	if ((cv = c_getvert(av[1])) == NULL)	/* get center vertex */
 		return(MG_EUNDEF);
-	xf_xfmpoint(cent, cv->p);
-	rad = xf_scale(atof(av[2]));
-	if ((inv = rad < 0.))
+	xf_xfmpoint(cent, cv->p);		/* transform center */
+	rad = xf_scale(atof(av[2]));		/* scale radius */
+	if ((inv = rad < 0.))			/* check for inversion */
 		rad = -rad;
-	if ((mat = material()) == NULL)
+	if ((mat = material()) == NULL)		/* get material */
 		return(MG_EBADMAT);
+						/* spit out primitive */
 	printf("\n%s %s %ss%d\n", mat, inv ? "bubble" : "sphere",
 			object(), ++nsphs);
 	printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n",
@@ -233,23 +263,24 @@ char	**av;
 	double	r1, r2;
 	C_VERTEX	*cv;
 	FVECT	cent, norm;
-
+					/* check argument count and type */
 	if (ac != 4)
 		return(MG_EARGC);
 	if (!isflt(av[2]) || !isflt(av[3]))
 		return(MG_ETYPE);
-	if ((cv = c_getvert(av[1])) == NULL)
+	if ((cv = c_getvert(av[1])) == NULL)	/* get center vertex */
 		return(MG_EUNDEF);
-	if (is0vect(cv->n))
+	if (is0vect(cv->n))			/* make sure we have normal */
 		return(MG_EILL);
-	xf_xfmpoint(cent, cv->p);
-	xf_rotvect(norm, cv->n);
-	r1 = xf_scale(atof(av[2]));
+	xf_xfmpoint(cent, cv->p);		/* transform center */
+	xf_rotvect(norm, cv->n);		/* rotate normal */
+	r1 = xf_scale(atof(av[2]));		/* scale radii */
 	r2 = xf_scale(atof(av[3]));
 	if (r1 < 0. | r2 <= r1)
 		return(MG_EILL);
-	if ((mat = material()) == NULL)
+	if ((mat = material()) == NULL)		/* get material */
 		return(MG_EBADMAT);
+						/* spit out primitive */
 	printf("\n%s ring %sr%d\n", mat, object(), ++nrings);
 	printf("0\n0\n8\n");
 	putv(cent);
@@ -270,29 +301,37 @@ char	**av;
 	register C_VERTEX	*cv;
 	FVECT	v;
 	int	rv;
-
+					/* check argument count and type */
 	if (ac < 4)
 		return(MG_EARGC);
-	if ((mat = material()) == NULL)
+	if ((mat = material()) == NULL)	/* get material */
 		return(MG_EBADMAT);
-	if (ac <= 5) {				/* check for surface normals */
+	if (ac <= 5) {				/* check for smoothing */
+		C_VERTEX	*cva[5];
 		for (i = 1; i < ac; i++) {
-			if ((cv = c_getvert(av[i])) == NULL)
+			if ((cva[i-1] = c_getvert(av[i])) == NULL)
 				return(MG_EUNDEF);
-			if (is0vect(cv->n))
+			if (is0vect(cva[i-1]->n))
 				break;
 		}
-		if (i == ac) {			/* break into triangles */
-			do_tri(mat, av[1], av[2], av[3]);
+		if (i == ac) {
+			i = flat_tri(cva[0]->p, cva[1]->p, cva[2]->p,
+					cva[0]->n, cva[1]->n, cva[2]->n);
+			if (i < 0)
+				return(MG_OK);	/* degenerate (error?) */
+		}
+		if (!i) {			/* smoothed triangles */
+			do_tri(mat, cva[0], cva[1], cva[2]);
 			if (ac == 5)
-				do_tri(mat, av[3], av[4], av[1]);
+				do_tri(mat, cva[2], cva[3], cva[0]);
 			return(MG_OK);
 		}
 	}
+					/* spit out unsmoothed primitive */
 	printf("\n%s polygon %sf%d\n", mat, object(), ++nfaces);
 	printf("0\n0\n%d\n", 3*(ac-1));
-	for (i = 1; i < ac; i++) {
-		if ((cv = c_getvert(av[i])) == NULL)
+	for (i = 1; i < ac; i++) {	/* get, transform, print each vertex */
+		if ((cv = c_getvert(av[invert ? ac-i : i])) == NULL)
 			return(MG_EUNDEF);
 		xf_xfmpoint(v, cv->p);
 		putv(v);
@@ -301,43 +340,54 @@ char	**av;
 }
 
 
+int
 r_ies(ac, av)				/* convert an IES luminaire file */
 int	ac;
 char	**av;
 {
 	int	xa0 = 2;
-	char	combuf[72];
+	char	combuf[128];
 	char	fname[48];
 	char	*oname;
 	register char	*op;
 	register int	i;
-
+					/* check argument count */
 	if (ac < 2)
 		return(MG_EARGC);
-	(void)strcpy(combuf, "ies2rad");
-	op = combuf + 7;
-	if (ac-xa0 >= 2 && !strcmp(av[xa0], "-m")) {
-		if (!isflt(av[xa0+1]))
-			return(MG_ETYPE);
-		op = addarg(addarg(op, "-m"), av[xa0+1]);
-		xa0 += 2;
-	}
-	if (access(av[1], 0) == -1)
-		return(MG_ENOFILE);
-	*op++ = ' ';			/* IES filename goes last */
-	(void)strcpy(op, av[1]);
-	system(combuf);			/* run ies2rad */
-					/* now let's find the output file */
-	if ((op = strrchr(av[1], '/')) == NULL)
+					/* construct output file name */
+	if ((op = strrchr(av[1], '/')) != NULL)
+		op++;
+	else
 		op = av[1];
 	(void)strcpy(fname, op);
 	if ((op = strrchr(fname, '.')) == NULL)
 		op = fname + strlen(fname);
 	(void)strcpy(op, ".rad");
-	if (access(fname, 0) == -1)
-		return(MG_EINCL);
-					/* put out xform command */
-	printf("\n!xform");
+					/* see if we need to run ies2rad */
+	if (access(fname, 0) == -1) {
+		(void)strcpy(combuf, "ies2rad");/* build ies2rad command */
+		op = combuf + 7;		/* get -m option (first) */
+		if (ac-xa0 >= 2 && !strcmp(av[xa0], "-m")) {
+			if (!isflt(av[xa0+1]))
+				return(MG_ETYPE);
+			op = addarg(addarg(op, "-m"), av[xa0+1]);
+			xa0 += 2;
+		}
+		*op++ = ' ';			/* build IES filename */
+		i = 0;
+		if (mg_file != NULL &&
+				(oname = strrchr(mg_file->fname,'/')) != NULL) {
+			i = oname - mg_file->fname + 1;
+			(void)strcpy(op, mg_file->fname);
+		}
+		(void)strcpy(op+i, av[1]);
+		if (access(op, 0) == -1)	/* check for file existence */
+			return(MG_ENOFILE);
+		system(combuf);			/* run ies2rad */
+		if (access(fname, 0) == -1)	/* check success */
+			return(MG_EINCL);
+	}
+	printf("\n!xform");			/* put out xform command */
 	oname = object();
 	if (*oname) {
 		printf(" -n ");
@@ -355,26 +405,30 @@ char	**av;
 }
 
 
-do_tri(mat, vn1, vn2, vn3)		/* put out smoothed triangle */
-char	*mat, *vn1, *vn2, *vn3;
+do_tri(mat, cv1, cv2, cv3)		/* put out smoothed triangle */
+char	*mat;
+C_VERTEX	*cv1, *cv2, *cv3;
 {
 	static int	ntris;
 	BARYCCM	bvecs;
 	FLOAT	bcoor[3][3];
-	C_VERTEX	*cv1, *cv2, *cv3;
+	C_VERTEX	*cvt;
 	FVECT	v1, v2, v3;
 	FVECT	n1, n2, n3;
 	register int	i;
-			/* the following is repeat code, so assume it's OK */
-	cv1 = c_getvert(vn1);
-	cv2 = c_getvert(vn2);
-	cv3 = c_getvert(vn3);
+
+	if (invert) {			/* swap vertex order if inverted */
+		cvt = cv1;
+		cv1 = cv3;
+		cv3 = cvt;
+	}
 	xf_xfmpoint(v1, cv1->p);
 	xf_xfmpoint(v2, cv2->p);
 	xf_xfmpoint(v3, cv3->p);
+					/* compute barycentric coords. */
 	if (comp_baryc(&bvecs, v1, v2, v3) < 0)
 		return;				/* degenerate triangle! */
-	printf("\n%s texfunc T-nor\n", mat);
+	printf("\n%s texfunc T-nor\n", mat);	/* put out texture */
 	printf("4 dx dy dz %s\n0\n", TCALNAME);
 	xf_rotvect(n1, cv1->n);
 	xf_rotvect(n2, cv2->n);
@@ -385,6 +439,7 @@ char	*mat, *vn1, *vn2, *vn3;
 		bcoor[i][2] = n3[i];
 	}
 	put_baryc(&bvecs, bcoor, 3);
+						/* put out triangle */
 	printf("\nT-nor polygon %st%d\n", object(), ++ntris);
 	printf("0\n0\n9\n");
 	putv(v1);
@@ -409,15 +464,15 @@ material()			/* get (and print) current material */
 	c_cmaterial->clock = 0;
 	if (c_cmaterial->ed > .1) {	/* emitter */
 		cvtcolor(radrgb, &c_cmaterial->ed_c,
-				emult*c_cmaterial->ed/WHTEFFICACY);
+				emult*c_cmaterial->ed/(PI*WHTEFFICACY));
 		if (glowdist < FHUGE) {		/* do a glow */
-			printf("\nvoid glow %s\n0\n0\n", mname);
-			printf("4 %f %f %f %f\n", colval(radrgb,RED),
+			fprintf(matfp, "\nvoid glow %s\n0\n0\n", mname);
+			fprintf(matfp, "4 %f %f %f %f\n", colval(radrgb,RED),
 					colval(radrgb,GRN),
 					colval(radrgb,BLU), glowdist);
 		} else {
-			printf("\nvoid light %s\n0\n0\n", mname);
-			printf("3 %f %f %f\n", colval(radrgb,RED),
+			fprintf(matfp, "\nvoid light %s\n0\n0\n", mname);
+			fprintf(matfp, "3 %f %f %f\n", colval(radrgb,RED),
 					colval(radrgb,GRN),
 					colval(radrgb,BLU));
 		}
@@ -425,13 +480,46 @@ material()			/* get (and print) current material */
 	}
 	d = c_cmaterial->rd + c_cmaterial->td +
 			c_cmaterial->rs + c_cmaterial->ts;
-	if (d <= 0. | d >= 1.)
+	if (d < 0. | d > 1.)
 		return(NULL);
+					/* check for glass/dielectric */
+	if (c_cmaterial->nr > 1.1 &&
+			c_cmaterial->ts > .25 && c_cmaterial->rs <= .125 &&
+			c_cmaterial->td <= .01 && c_cmaterial->rd <= .01 &&
+			c_cmaterial->rs_a <= .01 && c_cmaterial->ts_a <= .01) {
+		cvtcolor(radrgb, &c_cmaterial->ts_c,
+				c_cmaterial->ts + c_cmaterial->rs);
+		if (c_cmaterial->sided) {		/* dielectric */
+			colval(radrgb,RED) = pow(colval(radrgb,RED),
+							1./C_1SIDEDTHICK);
+			colval(radrgb,GRN) = pow(colval(radrgb,GRN),
+							1./C_1SIDEDTHICK);
+			colval(radrgb,BLU) = pow(colval(radrgb,BLU),
+							1./C_1SIDEDTHICK);
+			fprintf(matfp, "\nvoid dielectric %s\n0\n0\n", mname);
+			fprintf(matfp, "5 %g %g %g %f 0\n", colval(radrgb,RED),
+					colval(radrgb,GRN), colval(radrgb,BLU),
+					c_cmaterial->nr);
+			return(mname);
+		}
+							/* glass */
+		fprintf(matfp, "\nvoid glass %s\n0\n0\n", mname);
+		fprintf(matfp, "4 %f %f %f %f\n", colval(radrgb,RED),
+				colval(radrgb,GRN), colval(radrgb,BLU),
+				c_cmaterial->nr);
+		return(mname);
+		}
 					/* check for trans */
 	if (c_cmaterial->td > .01 || c_cmaterial->ts > .01) {
 		double	ts, a5, a6;
 
-		ts = sqrt(c_cmaterial->ts);	/* because we use 2 sides */
+		if (c_cmaterial->sided) {
+			ts = sqrt(c_cmaterial->ts);	/* approximate */
+			a5 = .5;
+		} else {
+			ts = c_cmaterial->ts;
+			a5 = 1.;
+		}
 						/* average colors */
 		d = c_cmaterial->rd + c_cmaterial->td + ts;
 		cvtcolor(radrgb, &c_cmaterial->rd_c, c_cmaterial->rd/d);
@@ -441,52 +529,47 @@ material()			/* get (and print) current material */
 		addcolor(radrgb, c2);
 		if (c_cmaterial->rs + ts > .0001)
 			a5 = (c_cmaterial->rs*c_cmaterial->rs_a +
-					ts*.5*c_cmaterial->ts_a) /
+					ts*a5*c_cmaterial->ts_a) /
 					(c_cmaterial->rs + ts);
 		a6 = (c_cmaterial->td + ts) /
 				(c_cmaterial->rd + c_cmaterial->td + ts);
-		if (a6 < .999) {
+		if (a6 < .999)
 			d = c_cmaterial->rd/(1. - c_cmaterial->rs)/(1. - a6);
-			scalecolor(radrgb, d);
-		}
-		printf("\nvoid trans %s\n0\n0\n", mname);
-		printf("7 %f %f %f\n", colval(radrgb,RED),
+		else
+			d = c_cmaterial->td + ts;
+		scalecolor(radrgb, d);
+		fprintf(matfp, "\nvoid trans %s\n0\n0\n", mname);
+		fprintf(matfp, "7 %f %f %f\n", colval(radrgb,RED),
 				colval(radrgb,GRN), colval(radrgb,BLU));
-		printf("\t%f %f %f %f\n", c_cmaterial->rs, a5, a6,
+		fprintf(matfp, "\t%f %f %f %f\n", c_cmaterial->rs, a5, a6,
 				ts/(ts + c_cmaterial->td));
 		return(mname);
 	}
 					/* check for plastic */
-	if (c_cmaterial->rs < .01 || c_isgrey(&c_cmaterial->rs_c)) {
-		if (c_cmaterial->rs > .999)
-			cvtcolor(radrgb, &c_cmaterial->rd_c, 1.);
-		else
-			cvtcolor(radrgb, &c_cmaterial->rd_c,
+	if (c_cmaterial->rs < .1) {
+		cvtcolor(radrgb, &c_cmaterial->rd_c,
 					c_cmaterial->rd/(1.-c_cmaterial->rs));
-		printf("\nvoid plastic %s\n0\n0\n", mname);
-		printf("5 %f %f %f %f %f\n", colval(radrgb,RED),
+		fprintf(matfp, "\nvoid plastic %s\n0\n0\n", mname);
+		fprintf(matfp, "5 %f %f %f %f %f\n", colval(radrgb,RED),
 				colval(radrgb,GRN), colval(radrgb,BLU),
 				c_cmaterial->rs, c_cmaterial->rs_a);
 		return(mname);
 	}
 					/* else it's metal */
-	d = c_cmaterial->rd + c_cmaterial->rs;	/* average colors */
-	cvtcolor(radrgb, &c_cmaterial->rd_c, c_cmaterial->rd/d);
-	cvtcolor(c2, &c_cmaterial->rs_c, c_cmaterial->rs/d);
+						/* average colors */
+	cvtcolor(radrgb, &c_cmaterial->rd_c, c_cmaterial->rd);
+	cvtcolor(c2, &c_cmaterial->rs_c, c_cmaterial->rs);
 	addcolor(radrgb, c2);
-	if (c_cmaterial->rs < .999) {
-		d = c_cmaterial->rd/(1. - c_cmaterial->rs);
-		scalecolor(radrgb, d);
-	}
-	printf("\nvoid metal %s\n0\n0\n", mname);
-	printf("5 %f %f %f %f %f\n", colval(radrgb,RED),
+	fprintf(matfp, "\nvoid metal %s\n0\n0\n", mname);
+	fprintf(matfp, "5 %f %f %f %f %f\n", colval(radrgb,RED),
 			colval(radrgb,GRN), colval(radrgb,BLU),
-			c_cmaterial->rs, c_cmaterial->rs_a);
+			c_cmaterial->rs/(c_cmaterial->rd + c_cmaterial->rs),
+			c_cmaterial->rs_a);
 	return(mname);
 }
 
 
-cvtcolor(radrgb, ciec, intensity)	/* convert a CIE color to Radiance */
+cvtcolor(radrgb, ciec, intensity)	/* convert a CIE XYZ color to RGB */
 COLOR	radrgb;
 register C_COLOR	*ciec;
 double	intensity;
@@ -508,7 +591,7 @@ object()			/* return current object name */
 	register int	i;
 	register char	*cp;
 	int	len;
-
+						/* tracked by obj_handler */
 	i = obj_nnames - sizeof(objbuf)/16;
 	if (i < 0)
 		i = 0;