[ViewVC] Diff of: radiance/ray/src/rt/ambcomp.c

Comparing ray/src/rt/ambcomp.c (file contents):
Revision 2.68 by greg, Thu Oct 23 18:19:14 2014 UTC vs.
Revision 2.92 by greg, Fri Apr 5 01:10:26 2024 UTC

#	Line 21 \| Line 21 \| static const char RCSid[] = "$Id$";
21		#include "ambient.h"
22		#include "random.h"
23
24	<	#ifndef OLDAMB
24	>	#ifndef MINADIV
25	>	#define MINADIV 7 /* minimum # divisions in each dimension */
26	>	#endif
27
26	–	extern void SDsquare2disk(double ds[2], double seedx, double seedy);
27	–
28		typedef struct {
29	–	COLOR v; /* hemisphere sample value */
30	–	float d; /* reciprocal distance (1/rt) */
29		FVECT p; /* intersection point */
30	+	float d; /* reciprocal distance */
31	+	SCOLOR v; /* hemisphere sample value */
32		} AMBSAMP; /* sample value */
33
34		typedef struct {
35		RAY rp; / originating ray sample */
36		int ns; /* number of samples per axis */
37		int sampOK; /* acquired full sample set? */
38	<	COLOR acoef; /* division contribution coefficient */
39	<	double acol[3]; /* accumulated color */
38	>	int atyp; /* RAMBIENT or TAMBIENT */
39	>	SCOLOR acoef; /* division contribution coefficient */
40	>	SCOLOR acol; /* accumulated color */
41	>	FVECT onrm; /* oriented unperturbed surface normal */
42		FVECT ux, uy; /* tangent axis unit vectors */
43		AMBSAMP sa[1]; /* sample array (extends struct) */
44		} AMBHEMI; /* ambient sample hemisphere */
#	Line 51 \| Line 53 \| typedef struct {
53
54
55		static int
56	+	ambcollision( /* proposed direciton collides? */
57	+	AMBHEMI *hp,
58	+	int i,
59	+	int j,
60	+	FVECT dv
61	+	)
62	+	{
63	+	double cos_thresh;
64	+	int ii, jj;
65	+	/* min. spacing = 1/4th division */
66	+	cos_thresh = (PI/4.)/(double)hp->ns;
67	+	cos_thresh = 1. - .5cos_threshcos_thresh;
68	+	/* check existing neighbors */
69	+	for (ii = i-1; ii <= i+1; ii++) {
70	+	if (ii < 0) continue;
71	+	if (ii >= hp->ns) break;
72	+	for (jj = j-1; jj <= j+1; jj++) {
73	+	AMBSAMP *ap;
74	+	FVECT avec;
75	+	double dprod;
76	+	if (jj < 0) continue;
77	+	if (jj >= hp->ns) break;
78	+	if ((ii==i) & (jj==j)) continue;
79	+	ap = &ambsam(hp,ii,jj);
80	+	if (ap->d <= .5/FHUGE)
81	+	continue; /* no one home */
82	+	VSUB(avec, ap->p, hp->rp->rop);
83	+	dprod = DOT(avec, dv);
84	+	if (dprod >= cos_thresh*VLEN(avec))
85	+	return(1); /* collision */
86	+	}
87	+	}
88	+	return(0); /* nothing to worry about */
89	+	}
90	+
91	+
92	+	static int
93		ambsample( /* initial ambient division sample */
94		AMBHEMI *hp,
95		int i,
#	Line 61 \| Line 100 \| *ambsample( / initial ambient division sample /*
100		AMBSAMP *ap = &ambsam(hp,i,j);
101		RAY ar;
102		int hlist[3], ii;
103	<	double spt[2], zd;
103	>	RREAL spt[2];
104	>	double zd;
105		/* generate hemispherical sample */
106		/* ambient coefficient for weight */
107		if (ambacc > FTINY)
108	<	setcolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL);
108	>	setscolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL);
109		else
110	<	copycolor(ar.rcoef, hp->acoef);
111	<	if (rayorigin(&ar, AMBIENT, hp->rp, ar.rcoef) < 0)
110	>	copyscolor(ar.rcoef, hp->acoef);
111	>	if (rayorigin(&ar, hp->atyp, hp->rp, ar.rcoef) < 0)
112		return(0);
113		if (ambacc > FTINY) {
114	<	multcolor(ar.rcoef, hp->acoef);
115	<	scalecolor(ar.rcoef, 1./AVGREFL);
114	>	smultscolor(ar.rcoef, hp->acoef);
115	>	scalescolor(ar.rcoef, 1./AVGREFL);
116		}
117		hlist[0] = hp->rp->rno;
118		hlist[1] = j;
119		hlist[2] = i;
120		multisamp(spt, 2, urand(ilhash(hlist,3)+n));
121	<	/* avoid coincident samples */
122	<	if (!n && (0 < i) & (i < hp->ns-1) &&
83	<	(0 < j) & (j < hp->ns-1)) {
84	<	if ((spt[0] < 0.1) \| (spt[0] >= 0.9))
85	<	spt[0] = 0.1 + 0.8*frandom();
86	<	if ((spt[1] < 0.1) \| (spt[1] >= 0.9))
87	<	spt[1] = 0.1 + 0.8*frandom();
88	<	}
89	<	SDsquare2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns);
121	>	resample:
122	>	square2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns);
123		zd = sqrt(1. - spt[0]spt[0] - spt[1]spt[1]);
124		for (ii = 3; ii--; )
125		ar.rdir[ii] = spt[0]*hp->ux[ii] +
126		spt[1]*hp->uy[ii] +
127	<	zd*hp->rp->ron[ii];
127	>	zd*hp->onrm[ii];
128		checknorm(ar.rdir);
129	+	/* avoid coincident samples */
130	+	if (!n && ambcollision(hp, i, j, ar.rdir)) {
131	+	spt[0] = frandom(); spt[1] = frandom();
132	+	goto resample; /* reject this sample */
133	+	}
134		dimlist[ndims++] = AI(hp,i,j) + 90171;
135		rayvalue(&ar); /* evaluate ray */
136		ndims--;
137	<	if (ar.rt <= FTINY)
137	>	zd = raydistance(&ar);
138	>	if (zd <= FTINY)
139		return(0); /* should never happen */
140	<	multcolor(ar.rcol, ar.rcoef); /* apply coefficient */
141	<	if (ar.rtap->d < 1.0) / new/closer distance? */
142	<	ap->d = 1.0/ar.rt;
140	>	smultscolor(ar.rcol, ar.rcoef); /* apply coefficient */
141	>	if (zdap->d < 1.0) / new/closer distance? */
142	>	ap->d = 1.0/zd;
143		if (!n) { /* record first vertex & value */
144	<	if (ar.rt > 10.0*thescene.cusize)
145	<	ar.rt = 10.0*thescene.cusize;
146	<	VSUM(ap->p, ar.rorg, ar.rdir, ar.rt);
147	<	copycolor(ap->v, ar.rcol);
144	>	if (zd > 10.0*thescene.cusize + 1000.)
145	>	zd = 10.0*thescene.cusize + 1000.;
146	>	VSUM(ap->p, ar.rorg, ar.rdir, zd);
147	>	copyscolor(ap->v, ar.rcol);
148		} else { /* else update recorded value */
149	<	hp->acol[RED] -= colval(ap->v,RED);
111	<	hp->acol[GRN] -= colval(ap->v,GRN);
112	<	hp->acol[BLU] -= colval(ap->v,BLU);
149	>	sopscolor(hp->acol, -=, ap->v);
150		zd = 1.0/(double)(n+1);
151	<	scalecolor(ar.rcol, zd);
151	>	scalescolor(ar.rcol, zd);
152		zd *= (double)n;
153	<	scalecolor(ap->v, zd);
154	<	addcolor(ap->v, ar.rcol);
153	>	scalescolor(ap->v, zd);
154	>	saddscolor(ap->v, ar.rcol);
155		}
156	<	addcolor(hp->acol, ap->v); /* add to our sum */
156	>	saddscolor(hp->acol, ap->v); /* add to our sum */
157		return(1);
158		}
159
160
161	<	/* Estimate errors based on ambient division differences */
161	>	/* Estimate variance based on ambient division differences */
162		static float *
163		getambdiffs(AMBHEMI *hp)
164		{
165	+	const double normf = 1./bright(hp->acoef);
166		float earr = (float )calloc(hp->ns*hp->ns, sizeof(float));
167		float *ep;
168		AMBSAMP *ap;
169	<	double b, d2;
169	>	double b, b1, d2;
170		int i, j;
171
172		if (earr == NULL) /* out of memory? */
173		return(NULL);
174	<	/* compute squared neighbor diffs */
174	>	/* sum squared neighbor diffs */
175		for (ap = hp->sa, ep = earr, i = 0; i < hp->ns; i++)
176		for (j = 0; j < hp->ns; j++, ap++, ep++) {
177	<	b = bright(ap[0].v);
177	>	b = pbright(ap[0].v);
178		if (i) { /* from above */
179	<	d2 = b - bright(ap[-hp->ns].v);
180	<	d2 *= d2;
179	>	b1 = pbright(ap[-hp->ns].v);
180	>	d2 = b - b1;
181	>	d2 = d2normf/(b + b1 + FTINY);
182		ep[0] += d2;
183		ep[-hp->ns] += d2;
184		}
185		if (!j) continue;
186		/* from behind */
187	<	d2 = b - bright(ap[-1].v);
188	<	d2 *= d2;
187	>	b1 = pbright(ap[-1].v);
188	>	d2 = b - b1;
189	>	d2 = d2normf/(b + b1 + FTINY);
190		ep[0] += d2;
191		ep[-1] += d2;
192		if (!i) continue;
193		/* diagonal */
194	<	d2 = b - bright(ap[-hp->ns-1].v);
195	<	d2 *= d2;
194	>	b1 = pbright(ap[-hp->ns-1].v);
195	>	d2 = b - b1;
196	>	d2 = d2normf/(b + b1 + FTINY);
197		ep[0] += d2;
198		ep[-hp->ns-1] += d2;
199		}
#	Line 179 \| Line 220 \| *ambsupersamp(AMBHEMI hp, int cnt)**
220		{
221		float *earr = getambdiffs(hp);
222		double e2rem = 0;
182	–	AMBSAMP *ap;
223		float *ep;
224		int i, j, n, nss;
225
#	Line 189 \| Line 229 \| *ambsupersamp(AMBHEMI hp, int cnt)**
229		for (ep = earr + hp->ns*hp->ns; ep > earr; )
230		e2rem += *--ep;
231		ep = earr; /* perform super-sampling */
232	<	for (ap = hp->sa, i = 0; i < hp->ns; i++)
233	<	for (j = 0; j < hp->ns; j++, ap++) {
232	>	for (i = 0; i < hp->ns; i++)
233	>	for (j = 0; j < hp->ns; j++) {
234		if (e2rem <= FTINY)
235		goto done; /* nothing left to do */
236		nss = ep/e2remcnt + frandom();
237		for (n = 1; n <= nss && ambsample(hp,i,j,n); n++)
238	<	--cnt;
238	>	if (!--cnt) goto done;
239		e2rem -= ep++; / update remainder */
240		}
241		done:
#	Line 205 \| Line 245 \| done:
245
246		static AMBHEMI *
247		samp_hemi( /* sample indirect hemisphere */
248	<	COLOR rcol,
248	>	SCOLOR rcol,
249		RAY *r,
250		double wt
251		)
252		{
253	+	int backside = (wt < 0);
254		AMBHEMI *hp;
255		double d;
256		int n, i, j;
257	+	/* insignificance check */
258	+	d = sintens(rcol);
259	+	if (d <= FTINY)
260	+	return(NULL);
261		/* set number of divisions */
262	+	if (backside) wt = -wt;
263		if (ambacc <= FTINY &&
264	<	wt > (d = 0.8intens(rcol)r->rweight/(ambdiv*minweight)))
264	>	wt > (d = 0.8r->rweight/(ambdiv*minweight)))
265		wt = d; /* avoid ray termination */
266		n = sqrt(ambdiv * wt) + 0.5;
267	<	i = 1 + 5(ambacc > FTINY); / minimum number of samples */
268	<	if (n < i)
267	>	i = 1 + (MINADIV-1)*(ambacc > FTINY);
268	>	if (n < i) /* use minimum number of samples? */
269		n = i;
270		/* allocate sampling array */
271		hp = (AMBHEMI )malloc(sizeof(AMBHEMI) + sizeof(AMBSAMP)(n*n - 1));
272		if (hp == NULL)
273		error(SYSTEM, "out of memory in samp_hemi");
274	+
275	+	if (backside) {
276	+	hp->atyp = TAMBIENT;
277	+	hp->onrm[0] = -r->ron[0];
278	+	hp->onrm[1] = -r->ron[1];
279	+	hp->onrm[2] = -r->ron[2];
280	+	} else {
281	+	hp->atyp = RAMBIENT;
282	+	VCOPY(hp->onrm, r->ron);
283	+	}
284		hp->rp = r;
285		hp->ns = n;
286	<	hp->acol[RED] = hp->acol[GRN] = hp->acol[BLU] = 0.0;
286	>	scolorblack(hp->acol);
287		memset(hp->sa, 0, sizeof(AMBSAMP)nn);
288		hp->sampOK = 0;
289		/* assign coefficient */
290	<	copycolor(hp->acoef, rcol);
290	>	copyscolor(hp->acoef, rcol);
291		d = 1.0/(n*n);
292	<	scalecolor(hp->acoef, d);
292	>	scalescolor(hp->acoef, d);
293		/* make tangent plane axes */
294	<	hp->uy[0] = 0.5 - frandom();
239	<	hp->uy[1] = 0.5 - frandom();
240	<	hp->uy[2] = 0.5 - frandom();
241	<	for (i = 3; i--; )
242	<	if ((-0.6 < r->ron[i]) & (r->ron[i] < 0.6))
243	<	break;
244	<	if (i < 0)
294	>	if (!getperpendicular(hp->ux, hp->onrm, 1))
295		error(CONSISTENCY, "bad ray direction in samp_hemi");
296	<	hp->uy[i] = 1.0;
247	<	VCROSS(hp->ux, hp->uy, r->ron);
248	<	normalize(hp->ux);
249	<	VCROSS(hp->uy, r->ron, hp->ux);
296	>	VCROSS(hp->uy, hp->onrm, hp->ux);
297		/* sample divisions */
298		for (i = hp->ns; i--; )
299		for (j = hp->ns; j--; )
300		hp->sampOK += ambsample(hp, i, j, 0);
301	<	copycolor(rcol, hp->acol);
301	>	copyscolor(rcol, hp->acol);
302		if (!hp->sampOK) { /* utter failure? */
303		free(hp);
304		return(NULL);
#	Line 260 \| Line 307 \| *samp_hemi( / sample indirect hemisphere /*
307		hp->sampOK = -1; / soft failure */
308		return(hp);
309		}
310	+	if (hp->sampOK <= MINADIV*MINADIV)
311	+	return(hp); /* don't bother super-sampling */
312		n = ambssamp*wt + 0.5;
313		if (n > 8) { /* perform super-sampling? */
314		ambsupersamp(hp, n);
315	<	copycolor(rcol, hp->acol);
315	>	copyscolor(rcol, hp->acol);
316		}
317		return(hp); /* all is well */
318		}
#	Line 275 \| Line 324 \| *back_ambval(AMBHEMI hp, const int n1, const int n2, c**
324		{
325		if (hp->sa[n1].d <= hp->sa[n2].d) {
326		if (hp->sa[n1].d <= hp->sa[n3].d)
327	<	return(colval(hp->sa[n1].v,CIEY));
328	<	return(colval(hp->sa[n3].v,CIEY));
327	>	return(hp->sa[n1].v[0]);
328	>	return(hp->sa[n3].v[0]);
329		}
330		if (hp->sa[n2].d <= hp->sa[n3].d)
331	<	return(colval(hp->sa[n2].v,CIEY));
332	<	return(colval(hp->sa[n3].v,CIEY));
331	>	return(hp->sa[n2].v[0]);
332	>	return(hp->sa[n3].v[0]);
333		}
334
335
#	Line 509 \| Line 558 \| *ambHessian( / anisotropic radii & pos. gradient /*
558		for (j = 0; j < hp->ns-1; j++) {
559		comp_fftri(&fftr, hp, AI(hp,0,j), AI(hp,0,j+1));
560		if (hessrow != NULL)
561	<	comp_hessian(hessrow[j], &fftr, hp->rp->ron);
561	>	comp_hessian(hessrow[j], &fftr, hp->onrm);
562		if (gradrow != NULL)
563	<	comp_gradient(gradrow[j], &fftr, hp->rp->ron);
563	>	comp_gradient(gradrow[j], &fftr, hp->onrm);
564		}
565		/* sum each row of triangles */
566		for (i = 0; i < hp->ns-1; i++) {
#	Line 519 \| Line 568 \| *ambHessian( / anisotropic radii & pos. gradient /*
568		FVECT gradcol;
569		comp_fftri(&fftr, hp, AI(hp,i,0), AI(hp,i+1,0));
570		if (hessrow != NULL)
571	<	comp_hessian(hesscol, &fftr, hp->rp->ron);
571	>	comp_hessian(hesscol, &fftr, hp->onrm);
572		if (gradrow != NULL)
573	<	comp_gradient(gradcol, &fftr, hp->rp->ron);
573	>	comp_gradient(gradcol, &fftr, hp->onrm);
574		for (j = 0; j < hp->ns-1; j++) {
575		FVECT hessdia[3]; /* compute triangle contributions */
576		FVECT graddia;
#	Line 531 \| Line 580 \| *ambHessian( / anisotropic radii & pos. gradient /*
580		/* diagonal (inner) edge */
581		comp_fftri(&fftr, hp, AI(hp,i,j+1), AI(hp,i+1,j));
582		if (hessrow != NULL) {
583	<	comp_hessian(hessdia, &fftr, hp->rp->ron);
583	>	comp_hessian(hessdia, &fftr, hp->onrm);
584		rev_hessian(hesscol);
585		add2hessian(hessian, hessrow[j], hessdia, hesscol, backg);
586		}
587		if (gradrow != NULL) {
588	<	comp_gradient(graddia, &fftr, hp->rp->ron);
588	>	comp_gradient(graddia, &fftr, hp->onrm);
589		rev_gradient(gradcol);
590		add2gradient(gradient, gradrow[j], graddia, gradcol, backg);
591		}
592		/* initialize edge in next row */
593		comp_fftri(&fftr, hp, AI(hp,i+1,j+1), AI(hp,i+1,j));
594		if (hessrow != NULL)
595	<	comp_hessian(hessrow[j], &fftr, hp->rp->ron);
595	>	comp_hessian(hessrow[j], &fftr, hp->onrm);
596		if (gradrow != NULL)
597	<	comp_gradient(gradrow[j], &fftr, hp->rp->ron);
597	>	comp_gradient(gradrow[j], &fftr, hp->onrm);
598		/* new column edge & paired triangle */
599		backg = back_ambval(hp, AI(hp,i+1,j+1),
600		AI(hp,i+1,j), AI(hp,i,j+1));
601		comp_fftri(&fftr, hp, AI(hp,i,j+1), AI(hp,i+1,j+1));
602		if (hessrow != NULL) {
603	<	comp_hessian(hesscol, &fftr, hp->rp->ron);
603	>	comp_hessian(hesscol, &fftr, hp->onrm);
604		rev_hessian(hessdia);
605		add2hessian(hessian, hessrow[j], hessdia, hesscol, backg);
606		if (i < hp->ns-2)
607		rev_hessian(hessrow[j]);
608		}
609		if (gradrow != NULL) {
610	<	comp_gradient(gradcol, &fftr, hp->rp->ron);
610	>	comp_gradient(gradcol, &fftr, hp->onrm);
611		rev_gradient(graddia);
612		add2gradient(gradient, gradrow[j], graddia, gradcol, backg);
613		if (i < hp->ns-2)
#	Line 594 \| Line 643 \| *ambdirgrad(AMBHEMI hp, FVECT uv[2], float dg[2])**
643		/* use vector for azimuth + 90deg */
644		VSUB(vd, ap->p, hp->rp->rop);
645		/* brightness over cosine factor */
646	<	gfact = colval(ap->v,CIEY) / DOT(hp->rp->ron, vd);
646	>	gfact = ap->v[0] / DOT(hp->onrm, vd);
647		/* sine = proj_radius/vd_length */
648		dgsum[0] -= DOT(uv[1], vd) * gfact;
649		dgsum[1] += DOT(uv[0], vd) * gfact;
#	Line 618 \| Line 667 \| *ambcorral(AMBHEMI hp, FVECT uv[2], const double r0, c**
667		double ang, a1;
668		int i, j;
669		/* don't bother for a few samples */
670	<	if (hp->ns < 12)
670	>	if (hp->ns < 8)
671		return(0);
672		/* check distances overhead */
673		for (i = hp->ns*3/4; i-- > hp->ns>>2; )
#	Line 644 \| Line 693 \| *ambcorral(AMBHEMI hp, FVECT uv[2], const double r0, c**
693		for (a1 = ang-ang_res; a1 <= ang+ang_res; a1 += ang_step)
694		flgs \|= 1L<<(int)(16/PI(a1 + 2.PI*(a1 < 0)));
695		}
647	–	/* add low-angle incident (< 20deg) */
648	–	if (fabs(hp->rp->rod) <= 0.342) {
649	–	u = -DOT(hp->rp->rdir, uv[0]);
650	–	v = -DOT(hp->rp->rdir, uv[1]);
651	–	if ((r0r0uu + r1r1vv) > hp->rp->rot*hp->rp->rot) {
652	–	ang = atan2a(v, u);
653	–	ang += 2.PI(ang < 0);
654	–	ang *= 16/PI;
655	–	if ((ang < .5) \| (ang >= 31.5))
656	–	flgs \|= 0x80000001;
657	–	else
658	–	flgs \|= 3L<<(int)(ang-.5);
659	–	}
660	–	}
696		return(flgs);
697		}
698
699
700		int
701		doambient( /* compute ambient component */
702	<	COLOR rcol, /* input/output color */
702	>	SCOLOR rcol, /* input/output color */
703		RAY *r,
704	<	double wt,
704	>	double wt, /* negative for back side */
705		FVECT uv[2], /* returned (optional) */
706		float ra[2], /* returned (optional) */
707		float pg[2], /* returned (optional) */
#	Line 694 \| Line 729 \| *doambient( / compute ambient component /*
729		return(0);
730
731		if ((ra == NULL) & (pg == NULL) & (dg == NULL) \|\|
732	<	(hp->sampOK < 0) \| (hp->ns < 6)) {
732	>	(hp->sampOK < 0) \| (hp->ns < MINADIV)) {
733		free(hp); /* Hessian not requested/possible */
734		return(-1); /* value-only return value */
735		}
736	<	if ((d = bright(rcol)) > FTINY) { /* normalize Y values */
737	<	d = 0.99(hp->nshp->ns)/d;
736	>	if ((d = scolor_mean(rcol)) > FTINY) {
737	>	d = 0.99(hp->nshp->ns)/d; /* normalize avg. values */
738		K = 0.01;
739		} else { /* or fall back on geometric Hessian */
740		K = 1.0;
#	Line 707 \| Line 742 \| *doambient( / compute ambient component /*
742		dg = NULL;
743		crlp = NULL;
744		}
745	<	ap = hp->sa; /* relative Y channel from here on... */
745	>	ap = hp->sa; /* single channel from here on... */
746		for (i = hp->ns*hp->ns; i--; ap++)
747	<	colval(ap->v,CIEY) = bright(ap->v)*d + K;
747	>	ap->v[0] = scolor_mean(ap->v)*d + K;
748
749		if (uv == NULL) /* make sure we have axis pointers */
750		uv = my_uv;
#	Line 733 \| Line 768 \| *doambient( / compute ambient component /*
768		if (ra[1] < minarad)
769		ra[1] = minarad;
770		}
771	<	ra[0] *= d = 1.0/sqrt(wt);
771	>	ra[0] *= d = 1.0/sqrt(fabs(wt));
772		if ((ra[1] = d) > 2.0ra[0])
773		ra[1] = 2.0*ra[0];
774		if (ra[1] > maxarad) {
#	Line 742 \| Line 777 \| *doambient( / compute ambient component /*
777		ra[0] = maxarad;
778		}
779		/* flag encroached directions */
780	<	if ((wt >= 0.89*AVGREFL) & (crlp != NULL))
780	>	if (crlp != NULL) /* XXX doesn't update with changes to ambacc */
781		crlp = ambcorral(hp, uv, ra[0]ambacc, ra[1]*ambacc);
782		if (pg != NULL) { /* cap gradient if necessary */
783		d = pg[0]pg[0]ra[0]ra[0] + pg[1]pg[1]ra[1]ra[1];
#	Line 756 \| Line 791 \| *doambient( / compute ambient component /*
791		free(hp); /* clean up and return */
792		return(1);
793		}
759	–
760	–
761	–	#else /* ! NEWAMB */
762	–
763	–
764	–	void
765	–	inithemi( /* initialize sampling hemisphere */
766	–	AMBHEMI *hp,
767	–	COLOR ac,
768	–	RAY *r,
769	–	double wt
770	–	)
771	–	{
772	–	double d;
773	–	int i;
774	–	/* set number of divisions */
775	–	if (ambacc <= FTINY &&
776	–	wt > (d = 0.8intens(ac)r->rweight/(ambdiv*minweight)))
777	–	wt = d; /* avoid ray termination */
778	–	hp->nt = sqrt(ambdiv * wt / PI) + 0.5;
779	–	i = ambacc > FTINY ? 3 : 1; /* minimum number of samples */
780	–	if (hp->nt < i)
781	–	hp->nt = i;
782	–	hp->np = PI * hp->nt + 0.5;
783	–	/* set number of super-samples */
784	–	hp->ns = ambssamp * wt + 0.5;
785	–	/* assign coefficient */
786	–	copycolor(hp->acoef, ac);
787	–	d = 1.0/(hp->nt*hp->np);
788	–	scalecolor(hp->acoef, d);
789	–	/* make axes */
790	–	VCOPY(hp->uz, r->ron);
791	–	hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0;
792	–	for (i = 0; i < 3; i++)
793	–	if (hp->uz[i] < 0.6 && hp->uz[i] > -0.6)
794	–	break;
795	–	if (i >= 3)
796	–	error(CONSISTENCY, "bad ray direction in inithemi");
797	–	hp->uy[i] = 1.0;
798	–	fcross(hp->ux, hp->uy, hp->uz);
799	–	normalize(hp->ux);
800	–	fcross(hp->uy, hp->uz, hp->ux);
801	–	}
802	–
803	–
804	–	int
805	–	divsample( /* sample a division */
806	–	AMBSAMP *dp,
807	–	AMBHEMI *h,
808	–	RAY *r
809	–	)
810	–	{
811	–	RAY ar;
812	–	int hlist[3];
813	–	double spt[2];
814	–	double xd, yd, zd;
815	–	double b2;
816	–	double phi;
817	–	int i;
818	–	/* ambient coefficient for weight */
819	–	if (ambacc > FTINY)
820	–	setcolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL);
821	–	else
822	–	copycolor(ar.rcoef, h->acoef);
823	–	if (rayorigin(&ar, AMBIENT, r, ar.rcoef) < 0)
824	–	return(-1);
825	–	if (ambacc > FTINY) {
826	–	multcolor(ar.rcoef, h->acoef);
827	–	scalecolor(ar.rcoef, 1./AVGREFL);
828	–	}
829	–	hlist[0] = r->rno;
830	–	hlist[1] = dp->t;
831	–	hlist[2] = dp->p;
832	–	multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n));
833	–	zd = sqrt((dp->t + spt[0])/h->nt);
834	–	phi = 2.0PI (dp->p + spt[1])/h->np;
835	–	xd = tcos(phi) * zd;
836	–	yd = tsin(phi) * zd;
837	–	zd = sqrt(1.0 - zd*zd);
838	–	for (i = 0; i < 3; i++)
839	–	ar.rdir[i] = xd*h->ux[i] +
840	–	yd*h->uy[i] +
841	–	zd*h->uz[i];
842	–	checknorm(ar.rdir);
843	–	dimlist[ndims++] = dp->t*h->np + dp->p + 90171;
844	–	rayvalue(&ar);
845	–	ndims--;
846	–	multcolor(ar.rcol, ar.rcoef); /* apply coefficient */
847	–	addcolor(dp->v, ar.rcol);
848	–	/* use rt to improve gradient calc */
849	–	if (ar.rt > FTINY && ar.rt < FHUGE)
850	–	dp->r += 1.0/ar.rt;
851	–	/* (re)initialize error */
852	–	if (dp->n++) {
853	–	b2 = bright(dp->v)/dp->n - bright(ar.rcol);
854	–	b2 = b2b2 + dp->k((dp->n-1)*(dp->n-1));
855	–	dp->k = b2/(dp->n*dp->n);
856	–	} else
857	–	dp->k = 0.0;
858	–	return(0);
859	–	}
860	–
861	–
862	–	static int
863	–	ambcmp( /* decreasing order */
864	–	const void *p1,
865	–	const void *p2
866	–	)
867	–	{
868	–	const AMBSAMP d1 = (const AMBSAMP )p1;
869	–	const AMBSAMP d2 = (const AMBSAMP )p2;
870	–
871	–	if (d1->k < d2->k)
872	–	return(1);
873	–	if (d1->k > d2->k)
874	–	return(-1);
875	–	return(0);
876	–	}
877	–
878	–
879	–	static int
880	–	ambnorm( /* standard order */
881	–	const void *p1,
882	–	const void *p2
883	–	)
884	–	{
885	–	const AMBSAMP d1 = (const AMBSAMP )p1;
886	–	const AMBSAMP d2 = (const AMBSAMP )p2;
887	–	int c;
888	–
889	–	if ( (c = d1->t - d2->t) )
890	–	return(c);
891	–	return(d1->p - d2->p);
892	–	}
893	–
894	–
895	–	double
896	–	doambient( /* compute ambient component */
897	–	COLOR rcol,
898	–	RAY *r,
899	–	double wt,
900	–	FVECT pg,
901	–	FVECT dg
902	–	)
903	–	{
904	–	double b, d=0;
905	–	AMBHEMI hemi;
906	–	AMBSAMP *div;
907	–	AMBSAMP dnew;
908	–	double acol[3];
909	–	AMBSAMP *dp;
910	–	double arad;
911	–	int divcnt;
912	–	int i, j;
913	–	/* initialize hemisphere */
914	–	inithemi(&hemi, rcol, r, wt);
915	–	divcnt = hemi.nt * hemi.np;
916	–	/* initialize */
917	–	if (pg != NULL)
918	–	pg[0] = pg[1] = pg[2] = 0.0;
919	–	if (dg != NULL)
920	–	dg[0] = dg[1] = dg[2] = 0.0;
921	–	setcolor(rcol, 0.0, 0.0, 0.0);
922	–	if (divcnt == 0)
923	–	return(0.0);
924	–	/* allocate super-samples */
925	–	if (hemi.ns > 0 \|\| pg != NULL \|\| dg != NULL) {
926	–	div = (AMBSAMP )malloc(divcntsizeof(AMBSAMP));
927	–	if (div == NULL)
928	–	error(SYSTEM, "out of memory in doambient");
929	–	} else
930	–	div = NULL;
931	–	/* sample the divisions */
932	–	arad = 0.0;
933	–	acol[0] = acol[1] = acol[2] = 0.0;
934	–	if ((dp = div) == NULL)
935	–	dp = &dnew;
936	–	divcnt = 0;
937	–	for (i = 0; i < hemi.nt; i++)
938	–	for (j = 0; j < hemi.np; j++) {
939	–	dp->t = i; dp->p = j;
940	–	setcolor(dp->v, 0.0, 0.0, 0.0);
941	–	dp->r = 0.0;
942	–	dp->n = 0;
943	–	if (divsample(dp, &hemi, r) < 0) {
944	–	if (div != NULL)
945	–	dp++;
946	–	continue;
947	–	}
948	–	arad += dp->r;
949	–	divcnt++;
950	–	if (div != NULL)
951	–	dp++;
952	–	else
953	–	addcolor(acol, dp->v);
954	–	}
955	–	if (!divcnt) {
956	–	if (div != NULL)
957	–	free((void *)div);
958	–	return(0.0); /* no samples taken */
959	–	}
960	–	if (divcnt < hemi.nt*hemi.np) {
961	–	pg = dg = NULL; /* incomplete sampling */
962	–	hemi.ns = 0;
963	–	} else if (arad > FTINY && divcnt/arad < minarad) {
964	–	hemi.ns = 0; /* close enough */
965	–	} else if (hemi.ns > 0) { /* else perform super-sampling? */
966	–	comperrs(div, &hemi); /* compute errors */
967	–	qsort(div, divcnt, sizeof(AMBSAMP), ambcmp); /* sort divs */
968	–	/* super-sample */
969	–	for (i = hemi.ns; i > 0; i--) {
970	–	dnew = *div;
971	–	if (divsample(&dnew, &hemi, r) < 0) {
972	–	dp++;
973	–	continue;
974	–	}
975	–	dp = div; /* reinsert */
976	–	j = divcnt < i ? divcnt : i;
977	–	while (--j > 0 && dnew.k < dp[1].k) {
978	–	dp = (dp+1);
979	–	dp++;
980	–	}
981	–	*dp = dnew;
982	–	}
983	–	if (pg != NULL \|\| dg != NULL) /* restore order */
984	–	qsort(div, divcnt, sizeof(AMBSAMP), ambnorm);
985	–	}
986	–	/* compute returned values */
987	–	if (div != NULL) {
988	–	arad = 0.0; /* note: divcnt may be < ntnp /
989	–	for (i = hemi.nt*hemi.np, dp = div; i-- > 0; dp++) {
990	–	arad += dp->r;
991	–	if (dp->n > 1) {
992	–	b = 1.0/dp->n;
993	–	scalecolor(dp->v, b);
994	–	dp->r *= b;
995	–	dp->n = 1;
996	–	}
997	–	addcolor(acol, dp->v);
998	–	}
999	–	b = bright(acol);
1000	–	if (b > FTINY) {
1001	–	b = 1.0/b; /* compute & normalize gradient(s) */
1002	–	if (pg != NULL) {
1003	–	posgradient(pg, div, &hemi);
1004	–	for (i = 0; i < 3; i++)
1005	–	pg[i] *= b;
1006	–	}
1007	–	if (dg != NULL) {
1008	–	dirgradient(dg, div, &hemi);
1009	–	for (i = 0; i < 3; i++)
1010	–	dg[i] *= b;
1011	–	}
1012	–	}
1013	–	free((void *)div);
1014	–	}
1015	–	copycolor(rcol, acol);
1016	–	if (arad <= FTINY)
1017	–	arad = maxarad;
1018	–	else
1019	–	arad = (divcnt+hemi.ns)/arad;
1020	–	if (pg != NULL) { /* reduce radius if gradient large */
1021	–	d = DOT(pg,pg);
1022	–	if (daradarad > 1.0)
1023	–	arad = 1.0/sqrt(d);
1024	–	}
1025	–	if (arad < minarad) {
1026	–	arad = minarad;
1027	–	if (pg != NULL && daradarad > 1.0) { /* cap gradient */
1028	–	d = 1.0/arad/sqrt(d);
1029	–	for (i = 0; i < 3; i++)
1030	–	pg[i] *= d;
1031	–	}
1032	–	}
1033	–	if ((arad /= sqrt(wt)) > maxarad)
1034	–	arad = maxarad;
1035	–	return(arad);
1036	–	}
1037	–
1038	–
1039	–	void
1040	–	comperrs( /* compute initial error estimates */
1041	–	AMBSAMP da, / assumes standard ordering */
1042	–	AMBHEMI *hp
1043	–	)
1044	–	{
1045	–	double b, b2;
1046	–	int i, j;
1047	–	AMBSAMP *dp;
1048	–	/* sum differences from neighbors */
1049	–	dp = da;
1050	–	for (i = 0; i < hp->nt; i++)
1051	–	for (j = 0; j < hp->np; j++) {
1052	–	#ifdef DEBUG
1053	–	if (dp->t != i \|\| dp->p != j)
1054	–	error(CONSISTENCY,
1055	–	"division order in comperrs");
1056	–	#endif
1057	–	b = bright(dp[0].v);
1058	–	if (i > 0) { /* from above */
1059	–	b2 = bright(dp[-hp->np].v) - b;
1060	–	b2 = b2 0.25;
1061	–	dp[0].k += b2;
1062	–	dp[-hp->np].k += b2;
1063	–	}
1064	–	if (j > 0) { /* from behind */
1065	–	b2 = bright(dp[-1].v) - b;
1066	–	b2 = b2 0.25;
1067	–	dp[0].k += b2;
1068	–	dp[-1].k += b2;
1069	–	} else { /* around */
1070	–	b2 = bright(dp[hp->np-1].v) - b;
1071	–	b2 = b2 0.25;
1072	–	dp[0].k += b2;
1073	–	dp[hp->np-1].k += b2;
1074	–	}
1075	–	dp++;
1076	–	}
1077	–	/* divide by number of neighbors */
1078	–	dp = da;
1079	–	for (j = 0; j < hp->np; j++) /* top row */
1080	–	(dp++)->k *= 1.0/3.0;
1081	–	if (hp->nt < 2)
1082	–	return;
1083	–	for (i = 1; i < hp->nt-1; i++) /* central region */
1084	–	for (j = 0; j < hp->np; j++)
1085	–	(dp++)->k *= 0.25;
1086	–	for (j = 0; j < hp->np; j++) /* bottom row */
1087	–	(dp++)->k *= 1.0/3.0;
1088	–	}
1089	–
1090	–
1091	–	void
1092	–	posgradient( /* compute position gradient */
1093	–	FVECT gv,
1094	–	AMBSAMP da, / assumes standard ordering */
1095	–	AMBHEMI *hp
1096	–	)
1097	–	{
1098	–	int i, j;
1099	–	double nextsine, lastsine, b, d;
1100	–	double mag0, mag1;
1101	–	double phi, cosp, sinp, xd, yd;
1102	–	AMBSAMP *dp;
1103	–
1104	–	xd = yd = 0.0;
1105	–	for (j = 0; j < hp->np; j++) {
1106	–	dp = da + j;
1107	–	mag0 = mag1 = 0.0;
1108	–	lastsine = 0.0;
1109	–	for (i = 0; i < hp->nt; i++) {
1110	–	#ifdef DEBUG
1111	–	if (dp->t != i \|\| dp->p != j)
1112	–	error(CONSISTENCY,
1113	–	"division order in posgradient");
1114	–	#endif
1115	–	b = bright(dp->v);
1116	–	if (i > 0) {
1117	–	d = dp[-hp->np].r;
1118	–	if (dp[0].r > d) d = dp[0].r;
1119	–	/* sin(t)cos(t)^2 /
1120	–	d = lastsine (1.0 - (double)i/hp->nt);
1121	–	mag0 += d*(b - bright(dp[-hp->np].v));
1122	–	}
1123	–	nextsine = sqrt((double)(i+1)/hp->nt);
1124	–	if (j > 0) {
1125	–	d = dp[-1].r;
1126	–	if (dp[0].r > d) d = dp[0].r;
1127	–	mag1 += d * (nextsine - lastsine) *
1128	–	(b - bright(dp[-1].v));
1129	–	} else {
1130	–	d = dp[hp->np-1].r;
1131	–	if (dp[0].r > d) d = dp[0].r;
1132	–	mag1 += d * (nextsine - lastsine) *
1133	–	(b - bright(dp[hp->np-1].v));
1134	–	}
1135	–	dp += hp->np;
1136	–	lastsine = nextsine;
1137	–	}
1138	–	mag0 = 2.0PI / hp->np;
1139	–	phi = 2.0PI (double)j/hp->np;
1140	–	cosp = tcos(phi); sinp = tsin(phi);
1141	–	xd += mag0cosp - mag1sinp;
1142	–	yd += mag0sinp + mag1cosp;
1143	–	}
1144	–	for (i = 0; i < 3; i++)
1145	–	gv[i] = (xdhp->ux[i] + ydhp->uy[i])(hp->nthp->np)/PI;
1146	–	}
1147	–
1148	–
1149	–	void
1150	–	dirgradient( /* compute direction gradient */
1151	–	FVECT gv,
1152	–	AMBSAMP da, / assumes standard ordering */
1153	–	AMBHEMI *hp
1154	–	)
1155	–	{
1156	–	int i, j;
1157	–	double mag;
1158	–	double phi, xd, yd;
1159	–	AMBSAMP *dp;
1160	–
1161	–	xd = yd = 0.0;
1162	–	for (j = 0; j < hp->np; j++) {
1163	–	dp = da + j;
1164	–	mag = 0.0;
1165	–	for (i = 0; i < hp->nt; i++) {
1166	–	#ifdef DEBUG
1167	–	if (dp->t != i \|\| dp->p != j)
1168	–	error(CONSISTENCY,
1169	–	"division order in dirgradient");
1170	–	#endif
1171	–	/* tan(t) */
1172	–	mag += bright(dp->v)/sqrt(hp->nt/(i+.5) - 1.0);
1173	–	dp += hp->np;
1174	–	}
1175	–	phi = 2.0PI (j+.5)/hp->np + PI/2.0;
1176	–	xd += mag * tcos(phi);
1177	–	yd += mag * tsin(phi);
1178	–	}
1179	–	for (i = 0; i < 3; i++)
1180	–	gv[i] = xdhp->ux[i] + ydhp->uy[i];
1181	–	}
1182	–
1183	–	#endif /* ! NEWAMB */

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Comparing ray/src/rt/ambcomp.c (file contents): Revision 2.68 by greg, Thu Oct 23 18:19:14 2014 UTC vs. Revision 2.92 by greg, Fri Apr 5 01:10:26 2024 UTC

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Comparing ray/src/rt/ambcomp.c (file contents):
Revision 2.68 by greg, Thu Oct 23 18:19:14 2014 UTC vs.
Revision 2.92 by greg, Fri Apr 5 01:10:26 2024 UTC