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root/Development/ray/src/rt/m_brdf.c

Comparing ray/src/rt/m_brdf.c (file contents):
Revision 2.4 by greg, Wed Oct 14 12:30:54 1992 UTC vs.
Revision 2.14 by greg, Wed Nov 22 09:27:53 1995 UTC

#	Line 16 | Line 16 | static char SCCSid[] = "$SunId$ LBL";
16
17		#include  "func.h"
18
19	+	extern int  backvis;                    /* back faces visible? */
20	+
21		/*
22		*      Arguments to this material include the color and specularity.
23		*  String arguments include the reflection function and files.
24		*  The BRDF is currently used just for the specular component to light
25		*  sources.  Reflectance values or data coordinates are functions
26	<	*  of the direction to the light source.
26	>	*  of the direction to the light source.  (Data modification functions
27	>	*  are passed the source direction as args 2-4.)
28		*      We orient the surface towards the incoming ray, so a single
29		*  surface can be used to represent an infinitely thin object.
30		*
#	Line 51 | Line 54 | static char SCCSid[] = "$SunId$ LBL";
54		*              rbrtd   gbrtd   bbrtd
55		*              funcfile        transform
56		*      0
57	<	*      6+      red     grn     blu     rspec   trans   tspec   A7 ..
57	>	*      9+      rdf     gdf     bdf
58	>	*              rdb     gdb     bdb
59	>	*              rdt     gdt     bdt     A10 ..
60		*
61		*      In addition to the normal variables available to functions,
62		*  we define the following:
63		*              NxP, NyP, NzP -         perturbed surface normal
64		*              RdotP -                 perturbed ray dot product
65	<	*              CrP, CgP, CbP -         perturbed material color
65	>	*              CrP, CgP, CbP -         perturbed material color (or pattern)
66		*/
67
68		typedef struct {
69		OBJREC  *mp;            /* material pointer */
70		RAY  *pr;               /* intersected ray */
71		DATARRAY  *dp;          /* data array for PDATA, MDATA or TDATA */
72	<	COLOR  mcolor;          /* color of this material */
73	<	double  rspec;          /* specular reflection */
74	<	double  rdiff;          /* diffuse reflection */
75	<	double  trans;          /* transmissivity */
76	<	double  tspec;          /* specular transmission */
77	<	double  tdiff;          /* diffuse transmission */
72	>	COLOR  mcolor;          /* material (or pattern) color */
73	>	COLOR  rdiff;           /* diffuse reflection */
74	>	COLOR  tdiff;           /* diffuse transmission */
75	>	double  rspec;          /* specular reflectance (1 for BRDTF) */
76	>	double  trans;          /* transmissivity (.5 for BRDTF) */
77	>	double  tspec;          /* specular transmittance (1 for BRDTF) */
78		FVECT  pnorm;           /* perturbed surface normal */
79		double  pdot;           /* perturbed dot product */
80		}  BRDFDAT;             /* BRDF material data */
#	Line 85 | Line 90 | double  omega;                 /* light source size */
90		double  dtmp;
91		COLOR  ctmp;
92		FVECT  ldx;
93	<	double  lddx[3], pt[MAXDIM];
93	>	static double  vldx[5], pt[MAXDIM];
94		register char   **sa;
95		register int    i;
96	+	#define lddx (vldx+1)
97
98		setcolor(cval, 0.0, 0.0, 0.0);
99
#	Line 95 | Line 101 | double  omega;                 /* light source size */
101
102		if (ldot <= FTINY && ldot >= -FTINY)
103		return;         /* too close to grazing */
104	+
105		if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY)
106		return;         /* wrong side */
107
108	<	if (ldot > 0.0 && np->rdiff > FTINY) {
108	>	if (ldot > 0.0) {
109		/*
110		*  Compute and add diffuse reflected component to returned
111		*  color.  The diffuse reflected component will always be
112		*  modified by the color of the material.
113		*/
114	<	copycolor(ctmp, np->mcolor);
115	<	dtmp = ldot * omega * np->rdiff / PI;
114	>	copycolor(ctmp, np->rdiff);
115	>	dtmp = ldot * omega / PI;
116		scalecolor(ctmp, dtmp);
117		addcolor(cval, ctmp);
118	<	}
112	<	if (ldot < 0.0 && np->tdiff > FTINY) {
118	>	} else {
119		/*
120		*  Diffuse transmitted component.
121		*/
122	<	copycolor(ctmp, np->mcolor);
123	<	dtmp = -ldot * omega * np->tdiff / PI;
122	>	copycolor(ctmp, np->tdiff);
123	>	dtmp = -ldot * omega / PI;
124		scalecolor(ctmp, dtmp);
125		addcolor(cval, ctmp);
126		}
#	Line 128 | Line 134 | double  omega;                 /* light source size */
134		multv3(ldx, ldir, funcxf.xfm);
135		for (i = 0; i < 3; i++)
136		lddx[i] = ldx[i]/funcxf.sca;
137	+	lddx[3] = omega;
138		/* compute BRTDF */
139		if (np->mp->otype == MAT_BRTDF) {
140	<	colval(ctmp,RED) = funvalue(sa[6], 3, lddx);
140	>	if (sa[6][0] == '0')            /* special case */
141	>	colval(ctmp,RED) = 0.0;
142	>	else
143	>	colval(ctmp,RED) = funvalue(sa[6], 4, lddx);
144		if (!strcmp(sa[7],sa[6]))
145		colval(ctmp,GRN) = colval(ctmp,RED);
146		else
147	<	colval(ctmp,GRN) = funvalue(sa[7], 3, lddx);
147	>	colval(ctmp,GRN) = funvalue(sa[7], 4, lddx);
148		if (!strcmp(sa[8],sa[6]))
149		colval(ctmp,BLU) = colval(ctmp,RED);
150		else if (!strcmp(sa[8],sa[7]))
151		colval(ctmp,BLU) = colval(ctmp,GRN);
152		else
153	<	colval(ctmp,BLU) = funvalue(sa[8], 3, lddx);
153	>	colval(ctmp,BLU) = funvalue(sa[8], 4, lddx);
154		dtmp = bright(ctmp);
155		} else if (np->dp == NULL) {
156	<	dtmp = funvalue(sa[0], 3, lddx);
156	>	dtmp = funvalue(sa[0], 4, lddx);
157		setcolor(ctmp, dtmp, dtmp, dtmp);
158		} else {
159		for (i = 0; i < np->dp->nd; i++)
160	<	pt[i] = funvalue(sa[3+i], 3, lddx);
161	<	dtmp = datavalue(np->dp, pt);
162	<	dtmp = funvalue(sa[0], 1, &dtmp);
160	>	pt[i] = funvalue(sa[3+i], 4, lddx);
161	>	vldx[0] = datavalue(np->dp, pt);
162	>	dtmp = funvalue(sa[0], 5, vldx);
163		setcolor(ctmp, dtmp, dtmp, dtmp);
164		}
165		if (errno) {
#	Line 162 | Line 172 | double  omega;                 /* light source size */
172		/*
173		*  Compute reflected non-diffuse component.
174		*/
175	<	if (np->mp->otype == MAT_MFUNC || np->mp->otype == MAT_MDATA)
175	>	if (np->mp->otype == MAT_MFUNC | np->mp->otype == MAT_MDATA)
176		multcolor(ctmp, np->mcolor);
177		dtmp = ldot * omega * np->rspec;
178		scalecolor(ctmp, dtmp);
#	Line 171 | Line 181 | double  omega;                 /* light source size */
181		/*
182		*  Compute transmitted non-diffuse component.
183		*/
184	<	if (np->mp->otype == MAT_TFUNC || np->mp->otype == MAT_TDATA)
184	>	if (np->mp->otype == MAT_TFUNC | np->mp->otype == MAT_TDATA)
185		multcolor(ctmp, np->mcolor);
186		dtmp = -ldot * omega * np->tspec;
187		scalecolor(ctmp, dtmp);
188		addcolor(cval, ctmp);
189		}
190	+	#undef lddx
191		}
192
193
194	<	m_brdf(m, r)                    /* color a ray which hit a BRDF material */
194	>	m_brdf(m, r)                    /* color a ray which hit a BRDTfunc material */
195		register OBJREC  *m;
196		register RAY  *r;
197		{
187	–	int  minsa, minfa;
198		BRDFDAT  nd;
199	+	RAY  sr;
200		double  transtest, transdist;
201	+	int  hasrefl, hastrans;
202		COLOR  ctmp;
203	<	double  dtmp, tspect, rspecr;
204	<	MFUNC  *mf;
203	>	FVECT  vtmp;
204	>	register MFUNC  *mf;
205		register int  i;
206		/* check arguments */
207	<	switch (m->otype) {
208	<	case MAT_PFUNC: case MAT_MFUNC:
209	<	minsa = 2; minfa = 4; break;
210	<	case MAT_PDATA: case MAT_MDATA:
211	<	minsa = 4; minfa = 4; break;
212	<	case MAT_TFUNC:
213	<	minsa = 2; minfa = 6; break;
214	<	case MAT_TDATA:
215	<	minsa = 4; minfa = 6; break;
216	<	case MAT_BRTDF:
217	<	minsa = 10; minfa = 6; break;
207	>	if (m->oargs.nsargs < 10 | m->oargs.nfargs < 9)
208	>	objerror(m, USER, "bad # arguments");
209	>	nd.mp = m;
210	>	nd.pr = r;
211	>	/* dummy values */
212	>	nd.rspec = nd.tspec = 1.0;
213	>	nd.trans = 0.5;
214	>	/* diffuse reflectance */
215	>	if (r->rod > 0.0)
216	>	setcolor(nd.rdiff, m->oargs.farg[0],
217	>	m->oargs.farg[1],
218	>	m->oargs.farg[2]);
219	>	else
220	>	setcolor(nd.rdiff, m->oargs.farg[3],
221	>	m->oargs.farg[4],
222	>	m->oargs.farg[5]);
223	>	/* diffuse transmittance */
224	>	setcolor(nd.tdiff, m->oargs.farg[6],
225	>	m->oargs.farg[7],
226	>	m->oargs.farg[8]);
227	>	/* get modifiers */
228	>	raytexture(r, m->omod);
229	>	nd.pdot = raynormal(nd.pnorm, r);       /* perturb normal */
230	>	if (r->rod < 0.0) {                     /* orient perturbed values */
231	>	nd.pdot = -nd.pdot;
232	>	for (i = 0; i < 3; i++) {
233	>	nd.pnorm[i] = -nd.pnorm[i];
234	>	r->pert[i] = -r->pert[i];
235	>	}
236		}
237	<	if (m->oargs.nsargs < minsa || m->oargs.nfargs < minfa)
237	>	copycolor(nd.mcolor, r->pcol);          /* get pattern color */
238	>	multcolor(nd.rdiff, nd.mcolor);         /* modify diffuse values */
239	>	multcolor(nd.tdiff, nd.mcolor);
240	>	hasrefl = bright(nd.rdiff) > FTINY;
241	>	hastrans = bright(nd.tdiff) > FTINY;
242	>	/* load cal file */
243	>	nd.dp = NULL;
244	>	mf = getfunc(m, 9, 0x3f, 0);
245	>	/* compute transmitted ray */
246	>	setbrdfunc(&nd);
247	>	transtest = 0;
248	>	transdist = r->rot;
249	>	errno = 0;
250	>	setcolor(ctmp, evalue(mf->ep[3]),
251	>	evalue(mf->ep[4]),
252	>	evalue(mf->ep[5]));
253	>	if (errno)
254	>	objerror(m, WARNING, "compute error");
255	>	else if (rayorigin(&sr, r, TRANS, bright(ctmp)) == 0) {
256	>	if (!(r->crtype & SHADOW) &&
257	>	DOT(r->pert,r->pert) > FTINY*FTINY) {
258	>	for (i = 0; i < 3; i++) /* perturb direction */
259	>	sr.rdir[i] = r->rdir[i] - .75*r->pert[i];
260	>	if (normalize(sr.rdir) == 0.0) {
261	>	objerror(m, WARNING, "illegal perturbation");
262	>	VCOPY(sr.rdir, r->rdir);
263	>	}
264	>	} else {
265	>	VCOPY(sr.rdir, r->rdir);
266	>	transtest = 2;
267	>	}
268	>	rayvalue(&sr);
269	>	multcolor(sr.rcol, ctmp);
270	>	addcolor(r->rcol, sr.rcol);
271	>	transtest *= bright(sr.rcol);
272	>	transdist = r->rot + sr.rt;
273	>	}
274	>	if (r->crtype & SHADOW)                 /* the rest is shadow */
275	>	return(1);
276	>	/* compute reflected ray */
277	>	setbrdfunc(&nd);
278	>	errno = 0;
279	>	setcolor(ctmp, evalue(mf->ep[0]),
280	>	evalue(mf->ep[1]),
281	>	evalue(mf->ep[2]));
282	>	if (errno)
283	>	objerror(m, WARNING, "compute error");
284	>	else if (rayorigin(&sr, r, REFLECTED, bright(ctmp)) == 0) {
285	>	for (i = 0; i < 3; i++)
286	>	sr.rdir[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i];
287	>	rayvalue(&sr);
288	>	multcolor(sr.rcol, ctmp);
289	>	addcolor(r->rcol, sr.rcol);
290	>	}
291	>	/* compute ambient */
292	>	if (hasrefl) {
293	>	if (nd.pdot < 0.0) {
294	>	flipsurface(r);
295	>	vtmp[0] = -nd.pnorm[0];
296	>	vtmp[1] = -nd.pnorm[1];
297	>	vtmp[2] = -nd.pnorm[2];
298	>	} else
299	>	VCOPY(vtmp, nd.pnorm);
300	>	ambient(ctmp, r, vtmp);
301	>	multcolor(ctmp, nd.rdiff);
302	>	addcolor(r->rcol, ctmp);        /* add to returned color */
303	>	if (nd.pdot < 0.0)
304	>	flipsurface(r);
305	>	}
306	>	if (hastrans) {                         /* from other side */
307	>	if (nd.pdot > 0.0) {
308	>	flipsurface(r);
309	>	vtmp[0] = -nd.pnorm[0];
310	>	vtmp[1] = -nd.pnorm[1];
311	>	vtmp[2] = -nd.pnorm[2];
312	>	} else
313	>	VCOPY(vtmp, nd.pnorm);
314	>	ambient(ctmp, r, vtmp);
315	>	multcolor(ctmp, nd.tdiff);
316	>	addcolor(r->rcol, ctmp);
317	>	if (nd.pdot > 0.0)
318	>	flipsurface(r);
319	>	}
320	>	if (hasrefl | hastrans || m->oargs.sarg[6][0] != '0')
321	>	direct(r, dirbrdf, &nd);        /* add direct component */
322	>	/* check distance */
323	>	if (transtest > bright(r->rcol))
324	>	r->rt = transdist;
325	>
326	>	return(1);
327	>	}
328	>
329	>
330	>
331	>	m_brdf2(m, r)                   /* color a ray which hit a BRDF material */
332	>	register OBJREC  *m;
333	>	register RAY  *r;
334	>	{
335	>	BRDFDAT  nd;
336	>	COLOR  ctmp;
337	>	FVECT  vtmp;
338	>	double  dtmp;
339	>	/* always a shadow */
340	>	if (r->crtype & SHADOW)
341	>	return(1);
342	>	/* check arguments */
343	>	if (m->oargs.nsargs < (hasdata(m->otype)?4:2) | m->oargs.nfargs <
344	>	(m->otype==MAT_TFUNC|m->otype==MAT_TDATA?6:4))
345		objerror(m, USER, "bad # arguments");
346		nd.mp = m;
347		nd.pr = r;
348	+	/* get material color */
349	+	setcolor(nd.mcolor, m->oargs.farg[0],
350	+	m->oargs.farg[1],
351	+	m->oargs.farg[2]);
352		/* get specular component */
353		nd.rspec = m->oargs.farg[3];
354	<	/* compute transmission */
355	<	if (m->otype == MAT_TFUNC || m->otype == MAT_TDATA
215	<	|| m->otype == MAT_BRTDF) {
354	>	/* compute transmittance */
355	>	if (m->otype == MAT_TFUNC | m->otype == MAT_TDATA) {
356		nd.trans = m->oargs.farg[4]*(1.0 - nd.rspec);
357		nd.tspec = nd.trans * m->oargs.farg[5];
358	<	nd.tdiff = nd.trans - nd.tspec;
359	<	} else
360	<	nd.tdiff = nd.tspec = nd.trans = 0.0;
361	<	/* early shadow check */
362	<	if (r->crtype & SHADOW && (m->otype != MAT_BRTDF || nd.tspec <= FTINY))
363	<	return;
364	<	/* diffuse reflection */
365	<	nd.rdiff = 1.0 - nd.trans - nd.rspec;
366	<	/* get material color */
367	<	setcolor(nd.mcolor, m->oargs.farg[0],
368	<	m->oargs.farg[1],
369	<	m->oargs.farg[2]);
370	<	/* fix orientation */
371	<	if (r->rod < 0.0)
372	<	flipsurface(r);
358	>	dtmp = nd.trans - nd.tspec;
359	>	setcolor(nd.tdiff, dtmp, dtmp, dtmp);
360	>	} else {
361	>	nd.tspec = nd.trans = 0.0;
362	>	setcolor(nd.tdiff, 0.0, 0.0, 0.0);
363	>	}
364	>	/* compute reflectance */
365	>	dtmp = 1.0 - nd.trans - nd.rspec;
366	>	setcolor(nd.rdiff, dtmp, dtmp, dtmp);
367	>	/* check for back side */
368	>	if (r->rod < 0.0) {
369	>	if (!backvis && m->otype != MAT_TFUNC
370	>	&& m->otype != MAT_TDATA) {
371	>	raytrans(r);
372	>	return(1);
373	>	}
374	>	flipsurface(r);                 /* reorient if backvis */
375	>	}
376		/* get modifiers */
377		raytexture(r, m->omod);
378		nd.pdot = raynormal(nd.pnorm, r);       /* perturb normal */
379		multcolor(nd.mcolor, r->pcol);          /* modify material color */
380	<	transtest = 0;
380	>	multcolor(nd.rdiff, nd.mcolor);
381	>	multcolor(nd.tdiff, nd.mcolor);
382		/* load auxiliary files */
383		if (hasdata(m->otype)) {
384		nd.dp = getdata(m->oargs.sarg[1]);
385	<	i = (1 << nd.dp->nd) - 1;
242	<	mf = getfunc(m, 2, i<<3, 0);
243	<	} else if (m->otype == MAT_BRTDF) {
244	<	nd.dp = NULL;
245	<	mf = getfunc(m, 9, 0x3f, 0);
385	>	getfunc(m, 2, 0, 0);
386		} else {
387		nd.dp = NULL;
388	<	mf = getfunc(m, 1, 0, 0);
388	>	getfunc(m, 1, 0, 0);
389		}
250	–	/* set special variables */
251	–	setbrdfunc(&nd);
252	–	/* compute transmitted ray */
253	–	tspect = 0.;
254	–	if (m->otype == MAT_BRTDF && nd.tspec > FTINY) {
255	–	RAY  sr;
256	–	errno = 0;
257	–	setcolor(ctmp, evalue(mf->ep[3]),
258	–	evalue(mf->ep[4]),
259	–	evalue(mf->ep[5]));
260	–	scalecolor(ctmp, nd.trans);
261	–	if (errno)
262	–	objerror(m, WARNING, "compute error");
263	–	else if ((tspect = bright(ctmp)) > FTINY &&
264	–	rayorigin(&sr, r, TRANS, tspect) == 0) {
265	–	if (!(r->crtype & SHADOW) &&
266	–	DOT(r->pert,r->pert) > FTINY*FTINY) {
267	–	for (i = 0; i < 3; i++) /* perturb direction */
268	–	sr.rdir[i] = r->rdir[i] -
269	–	.75*r->pert[i];
270	–	if (normalize(sr.rdir) == 0.0) {
271	–	objerror(m, WARNING, "illegal perturbation");
272	–	VCOPY(sr.rdir, r->rdir);
273	–	}
274	–	} else {
275	–	VCOPY(sr.rdir, r->rdir);
276	–	transtest = 2;
277	–	}
278	–	rayvalue(&sr);
279	–	multcolor(sr.rcol, ctmp);
280	–	addcolor(r->rcol, sr.rcol);
281	–	transtest *= bright(sr.rcol);
282	–	transdist = r->rot + sr.rt;
283	–	}
284	–	}
285	–	if (r->crtype & SHADOW)                 /* the rest is shadow */
286	–	return;
287	–	/* compute reflected ray */
288	–	rspecr = 0.;
289	–	if (m->otype == MAT_BRTDF && nd.rspec > FTINY) {
290	–	RAY  sr;
291	–	errno = 0;
292	–	setcolor(ctmp, evalue(mf->ep[0]),
293	–	evalue(mf->ep[1]),
294	–	evalue(mf->ep[2]));
295	–	if (errno)
296	–	objerror(m, WARNING, "compute error");
297	–	else if ((rspecr = bright(ctmp)) > FTINY &&
298	–	rayorigin(&sr, r, REFLECTED, rspecr) == 0) {
299	–	for (i = 0; i < 3; i++)
300	–	sr.rdir[i] = r->rdir[i] +
301	–	2.0*nd.pdot*nd.pnorm[i];
302	–	rayvalue(&sr);
303	–	multcolor(sr.rcol, ctmp);
304	–	addcolor(r->rcol, sr.rcol);
305	–	}
306	–	}
390		/* compute ambient */
391	<	if ((dtmp = 1.0-nd.trans-rspecr) > FTINY) {
392	<	ambient(ctmp, r);
393	<	scalecolor(ctmp, dtmp);
391	>	if (nd.trans < 1.0-FTINY) {
392	>	ambient(ctmp, r, nd.pnorm);
393	>	scalecolor(ctmp, 1.0-nd.trans);
394		multcolor(ctmp, nd.mcolor);     /* modified by material color */
395		addcolor(r->rcol, ctmp);        /* add to returned color */
396		}
397	<	if ((dtmp = nd.trans-tspect) > FTINY) { /* from other side */
397	>	if (nd.trans > FTINY) {         /* from other side */
398		flipsurface(r);
399	<	ambient(ctmp, r);
400	<	scalecolor(ctmp, dtmp);
399	>	vtmp[0] = -nd.pnorm[0];
400	>	vtmp[1] = -nd.pnorm[1];
401	>	vtmp[2] = -nd.pnorm[2];
402	>	ambient(ctmp, r, vtmp);
403	>	scalecolor(ctmp, nd.trans);
404		multcolor(ctmp, nd.mcolor);
405		addcolor(r->rcol, ctmp);
406		flipsurface(r);
407		}
408		/* add direct component */
409		direct(r, dirbrdf, &nd);
410	<	/* check distance */
411	<	if (transtest > bright(r->rcol))
326	<	r->rt = transdist;
410	>
411	>	return(1);
412		}
413
414

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