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Comparing ray/src/rt/aniso.c (file contents):
Revision 2.13 by greg, Mon Apr 20 09:25:47 1992 UTC vs.
Revision 2.27 by greg, Wed Jan 12 16:46:32 1994 UTC

#	Line 19 | Line 19 | static char SCCSid[] = "$SunId$ LBL";
19		extern double  specthresh;              /* specular sampling threshold */
20		extern double  specjitter;              /* specular sampling jitter */
21
22	+	static  agaussamp(), getacoords();
23	+
24		/*
25	<	*      This anisotropic reflection model uses a variant on the
26	<	*  exponential Gaussian used in normal.c.
25	>	*      This routine implements the anisotropic Gaussian
26	>	*  model described by Ward in Siggraph `92 article.
27		*      We orient the surface towards the incoming ray, so a single
28		*  surface can be used to represent an infinitely thin object.
29		*
#	Line 68 | Line 70 | FVECT  ldir;                   /* light source direction */
70		double  omega;                  /* light source size */
71		{
72		double  ldot;
73	<	double  dtmp, dtmp2;
73	>	double  dtmp, dtmp1, dtmp2;
74		FVECT  h;
75		double  au2, av2;
76		COLOR  ctmp;
#	Line 101 | Line 103 | double  omega;                 /* light source size */
103		au2 = av2 = omega/(4.0*PI);
104		else
105		au2 = av2 = 0.0;
106	<	au2 += np->u_alpha * np->u_alpha;
107	<	av2 += np->v_alpha * np->v_alpha;
106	>	au2 += np->u_alpha*np->u_alpha;
107	>	av2 += np->v_alpha*np->v_alpha;
108		/* half vector */
109		h[0] = ldir[0] - np->rp->rdir[0];
110		h[1] = ldir[1] - np->rp->rdir[1];
111		h[2] = ldir[2] - np->rp->rdir[2];
110	–	normalize(h);
112		/* ellipse */
113	<	dtmp = DOT(np->u, h);
114	<	dtmp *= dtmp / au2;
113	>	dtmp1 = DOT(np->u, h);
114	>	dtmp1 *= dtmp1 / au2;
115		dtmp2 = DOT(np->v, h);
116		dtmp2 *= dtmp2 / av2;
117		/* gaussian */
118	<	dtmp = (dtmp + dtmp2) / (1.0 + DOT(np->pnorm, h));
119	<	dtmp = exp(-2.0*dtmp) / (4.0*PI * sqrt(au2*av2));
118	>	dtmp = DOT(np->pnorm, h);
119	>	dtmp = (dtmp1 + dtmp2) / (dtmp*dtmp);
120	>	dtmp = exp(-dtmp) * (0.25/PI)
121	>	* sqrt(ldot/(np->pdot*au2*av2));
122		/* worth using? */
123		if (dtmp > FTINY) {
124		copycolor(ctmp, np->scolor);
125	<	dtmp *= omega * sqrt(ldot/np->pdot);
125	>	dtmp *= omega;
126		scalecolor(ctmp, dtmp);
127		addcolor(cval, ctmp);
128		}
#	Line 139 | Line 142 | double  omega;                 /* light source size */
142		*  is always modified by material color.
143		*/
144		/* roughness + source */
145	+	au2 = av2 = omega / PI;
146	+	au2 += np->u_alpha*np->u_alpha;
147	+	av2 += np->v_alpha*np->v_alpha;
148	+	/* "half vector" */
149	+	h[0] = ldir[0] - np->prdir[0];
150	+	h[1] = ldir[1] - np->prdir[1];
151	+	h[2] = ldir[2] - np->prdir[2];
152	+	dtmp = DOT(h,h);
153	+	if (dtmp > FTINY*FTINY) {
154	+	dtmp1 = DOT(h,np->pnorm);
155	+	dtmp = 1.0 - dtmp1*dtmp1/dtmp;
156	+	if (dtmp > FTINY*FTINY) {
157	+	dtmp1 = DOT(h,np->u);
158	+	dtmp1 *= dtmp1 / au2;
159	+	dtmp2 = DOT(h,np->v);
160	+	dtmp2 *= dtmp2 / av2;
161	+	dtmp = (dtmp1 + dtmp2) / dtmp;
162	+	}
163	+	} else
164	+	dtmp = 0.0;
165		/* gaussian */
166	<	dtmp = 0.0;
166	>	dtmp = exp(-dtmp) * (1.0/PI)
167	>	* sqrt(-ldot/(np->pdot*au2*av2));
168		/* worth using? */
169		if (dtmp > FTINY) {
170		copycolor(ctmp, np->mcolor);
171	<	dtmp *= np->tspec * omega * sqrt(ldot/np->pdot);
171	>	dtmp *= np->tspec * omega;
172		scalecolor(ctmp, dtmp);
173		addcolor(cval, ctmp);
174		}
#	Line 157 | Line 181 | register OBJREC  *m;
181		register RAY  *r;
182		{
183		ANISODAT  nd;
160	–	double  dtmp;
184		COLOR  ctmp;
185		register int  i;
186		/* easy shadow test */
187		if (r->crtype & SHADOW)
188	<	return;
188	>	return(1);
189
190		if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6))
191		objerror(m, USER, "bad number of real arguments");
#	Line 176 | Line 199 | register RAY  *r;
199		nd.specfl = 0;
200		nd.u_alpha = m->oargs.farg[4];
201		nd.v_alpha = m->oargs.farg[5];
202	<	if (nd.u_alpha < 1e-6 || nd.v_alpha <= 1e-6)
202	>	if (nd.u_alpha < FTINY || nd.v_alpha <= FTINY)
203		objerror(m, USER, "roughness too small");
204		/* reorient if necessary */
205		if (r->rod < 0.0)
#	Line 197 | Line 220 | register RAY  *r;
220		setcolor(nd.scolor, 1.0, 1.0, 1.0);
221		scalecolor(nd.scolor, nd.rspec);
222		/* check threshold */
223	<	if (specthresh > FTINY &&
201	<	(specthresh >= 1.-FTINY ||
202	<	specthresh > nd.rspec))
223	>	if (specthresh >= nd.rspec-FTINY)
224		nd.specfl |= SP_RBLT;
225		/* compute refl. direction */
226		for (i = 0; i < 3; i++)
#	Line 209 | Line 230 | register RAY  *r;
230		nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
231		}
232		/* compute transmission */
233	<	if (m->otype == MAT_TRANS) {
233	>	if (m->otype == MAT_TRANS2) {
234		nd.trans = m->oargs.farg[6]*(1.0 - nd.rspec);
235		nd.tspec = nd.trans * m->oargs.farg[7];
236		nd.tdiff = nd.trans - nd.tspec;
237		if (nd.tspec > FTINY) {
238		nd.specfl |= SP_TRAN;
239		/* check threshold */
240	<	if (specthresh > FTINY &&
220	<	(specthresh >= 1.-FTINY ||
221	<	specthresh > nd.tspec))
240	>	if (specthresh >= nd.tspec-FTINY)
241		nd.specfl |= SP_TBLT;
242		if (DOT(r->pert,r->pert) <= FTINY*FTINY) {
243		VCOPY(nd.prdir, r->rdir);
244		} else {
245		for (i = 0; i < 3; i++)         /* perturb */
246	<	nd.prdir[i] = r->rdir[i] -
228	<	0.5*r->pert[i];
246	>	nd.prdir[i] = r->rdir[i] - r->pert[i];
247		if (DOT(nd.prdir, r->ron) < -FTINY)
248		normalize(nd.prdir);    /* OK */
249		else
#	Line 269 | Line 287 | register RAY  *r;
287		}
288		/* add direct component */
289		direct(r, diraniso, &nd);
290	+
291	+	return(1);
292		}
293
294
#	Line 290 | Line 310 | register ANISODAT  *np;
310		np->specfl |= SP_BADU;
311		return;
312		}
313	<	multv3(np->u, np->u, mf->f->xfm);
313	>	if (mf->f != &unitxf)
314	>	multv3(np->u, np->u, mf->f->xfm);
315		fcross(np->v, np->pnorm, np->u);
316		if (normalize(np->v) == 0.0) {
317		objerror(np->mp, WARNING, "illegal orientation vector");
#	Line 318 | Line 339 | register ANISODAT  *np;
339		d = urand(ilhash(dimlist,ndims)+samplendx);
340		multisamp(rv, 2, d);
341		d = 2.0*PI * rv[0];
342	<	cosp = np->u_alpha * cos(d);
343	<	sinp = np->v_alpha * sin(d);
342	>	cosp = cos(d) * np->u_alpha;
343	>	sinp = sin(d) * np->v_alpha;
344		d = sqrt(cosp*cosp + sinp*sinp);
345		cosp /= d;
346		sinp /= d;
#	Line 350 | Line 371 | register ANISODAT  *np;
371		d = urand(ilhash(dimlist,ndims)+1823+samplendx);
372		multisamp(rv, 2, d);
373		d = 2.0*PI * rv[0];
374	<	cosp = cos(d);
375	<	sinp = sin(d);
374	>	cosp = cos(d) * np->u_alpha;
375	>	sinp = sin(d) * np->v_alpha;
376	>	d = sqrt(cosp*cosp + sinp*sinp);
377	>	cosp /= d;
378	>	sinp /= d;
379		rv[1] = 1.0 - specjitter*rv[1];
380		if (rv[1] <= FTINY)
381		d = 1.0;
382		else
383		d = sqrt(-log(rv[1]) /
384	<	(cosp*cosp*4./(np->u_alpha*np->u_alpha) +
385	<	sinp*sinp*4./(np->v_alpha*np->v_alpha)));
384	>	(cosp*cosp/(np->u_alpha*np->u_alpha) +
385	>	sinp*sinp/(np->v_alpha*np->u_alpha)));
386		for (i = 0; i < 3; i++)
387		sr.rdir[i] = np->prdir[i] +
388		d*(cosp*np->u[i] + sinp*np->v[i]);

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