4 |
|
/* |
5 |
|
* Routines to compute "ambient" values using Monte Carlo |
6 |
|
* |
7 |
+ |
* Hessian calculations based on "Practical Hessian-Based Error Control |
8 |
+ |
* for Irradiance Caching" by Schwarzhaupt, Wann Jensen, & Jarosz |
9 |
+ |
* from ACM SIGGRAPH Asia 2012 conference proceedings. |
10 |
+ |
* |
11 |
+ |
* Added book-keeping optimization to avoid calculations that would |
12 |
+ |
* cancel due to traversal both directions on edges that are adjacent |
13 |
+ |
* to same-valued triangles. This cuts about half of Hessian math. |
14 |
+ |
* |
15 |
|
* Declarations of external symbols in ambient.h |
16 |
|
*/ |
17 |
|
|
18 |
|
#include "copyright.h" |
19 |
|
|
20 |
|
#include "ray.h" |
13 |
– |
|
21 |
|
#include "ambient.h" |
15 |
– |
|
22 |
|
#include "random.h" |
23 |
|
|
24 |
+ |
#ifndef MINADIV |
25 |
+ |
#define MINADIV 7 /* minimum # divisions in each dimension */ |
26 |
+ |
#endif |
27 |
+ |
#ifndef MINSDIST |
28 |
+ |
#define MINSDIST 0.25 /* def. min. spacing = 1/4th division */ |
29 |
+ |
#endif |
30 |
|
|
31 |
+ |
typedef struct { |
32 |
+ |
FVECT p; /* intersection point */ |
33 |
+ |
float d; /* reciprocal distance */ |
34 |
+ |
SCOLOR v; /* hemisphere sample value */ |
35 |
+ |
} AMBSAMP; /* sample value */ |
36 |
+ |
|
37 |
+ |
typedef struct { |
38 |
+ |
RAY *rp; /* originating ray sample */ |
39 |
+ |
int ns; /* number of samples per axis */ |
40 |
+ |
int sampOK; /* acquired full sample set? */ |
41 |
+ |
int atyp; /* RAMBIENT or TAMBIENT */ |
42 |
+ |
SCOLOR acoef; /* division contribution coefficient */ |
43 |
+ |
SCOLOR acol; /* accumulated color */ |
44 |
+ |
FVECT onrm; /* oriented unperturbed surface normal */ |
45 |
+ |
FVECT ux, uy; /* tangent axis unit vectors */ |
46 |
+ |
AMBSAMP sa[1]; /* sample array (extends struct) */ |
47 |
+ |
} AMBHEMI; /* ambient sample hemisphere */ |
48 |
+ |
|
49 |
+ |
#define AI(h,i,j) ((i)*(h)->ns + (j)) |
50 |
+ |
#define ambsam(h,i,j) (h)->sa[AI(h,i,j)] |
51 |
+ |
|
52 |
+ |
typedef struct { |
53 |
+ |
FVECT r_i, r_i1, e_i, rcp, rI2_eJ2; |
54 |
+ |
double I1, I2; |
55 |
+ |
} FFTRI; /* vectors and coefficients for Hessian calculation */ |
56 |
+ |
|
57 |
+ |
|
58 |
|
static int |
59 |
< |
ambcmp(d1, d2) /* decreasing order */ |
60 |
< |
AMBSAMP *d1, *d2; |
59 |
> |
ambcollision( /* proposed direciton collides? */ |
60 |
> |
AMBHEMI *hp, |
61 |
> |
int i, |
62 |
> |
int j, |
63 |
> |
FVECT dv |
64 |
> |
) |
65 |
|
{ |
66 |
< |
if (d1->k < d2->k) |
67 |
< |
return(1); |
68 |
< |
if (d1->k > d2->k) |
69 |
< |
return(-1); |
70 |
< |
return(0); |
66 |
> |
double cos_thresh; |
67 |
> |
int ii, jj; |
68 |
> |
|
69 |
> |
cos_thresh = (PI*MINSDIST)/(double)hp->ns; |
70 |
> |
cos_thresh = 1. - .5*cos_thresh*cos_thresh; |
71 |
> |
/* check existing neighbors */ |
72 |
> |
for (ii = i-1; ii <= i+1; ii++) { |
73 |
> |
if (ii < 0) continue; |
74 |
> |
if (ii >= hp->ns) break; |
75 |
> |
for (jj = j-1; jj <= j+1; jj++) { |
76 |
> |
AMBSAMP *ap; |
77 |
> |
FVECT avec; |
78 |
> |
double dprod; |
79 |
> |
if (jj < 0) continue; |
80 |
> |
if (jj >= hp->ns) break; |
81 |
> |
if ((ii==i) & (jj==j)) continue; |
82 |
> |
ap = &ambsam(hp,ii,jj); |
83 |
> |
if (ap->d <= .5/FHUGE) |
84 |
> |
continue; /* no one home */ |
85 |
> |
VSUB(avec, ap->p, hp->rp->rop); |
86 |
> |
dprod = DOT(avec, dv); |
87 |
> |
if (dprod >= cos_thresh*VLEN(avec)) |
88 |
> |
return(1); /* collision */ |
89 |
> |
} |
90 |
> |
} |
91 |
> |
return(0); /* nothing to worry about */ |
92 |
|
} |
93 |
|
|
94 |
|
|
95 |
+ |
#define XLOTSIZ 251 /* size of used car lot */ |
96 |
+ |
#define CFIRST 0 /* first corner */ |
97 |
+ |
#define COTHER (CFIRST+4) /* non-corner sample */ |
98 |
+ |
#define CMAXTARGET (int)(XLOTSIZ*MINSDIST/(1-MINSDIST)) |
99 |
+ |
#define CXCOPY(d,s) (excharr[d][0]=excharr[s][0], excharr[d][1]=excharr[s][1]) |
100 |
+ |
|
101 |
|
static int |
102 |
< |
ambnorm(d1, d2) /* standard order */ |
33 |
< |
AMBSAMP *d1, *d2; |
102 |
> |
psample_class(double ss[2]) /* classify patch sample */ |
103 |
|
{ |
104 |
< |
register int c; |
104 |
> |
if (ss[0] < MINSDIST) { |
105 |
> |
if (ss[1] < MINSDIST) |
106 |
> |
return(CFIRST); |
107 |
> |
if (ss[1] > 1.-MINSDIST) |
108 |
> |
return(CFIRST+2); |
109 |
> |
} else if (ss[0] > 1.-MINSDIST) { |
110 |
> |
if (ss[1] < MINSDIST) |
111 |
> |
return(CFIRST+1); |
112 |
> |
if (ss[1] > 1.-MINSDIST) |
113 |
> |
return(CFIRST+3); |
114 |
> |
} |
115 |
> |
return(COTHER); /* not in a corner */ |
116 |
> |
} |
117 |
|
|
118 |
< |
if ( (c = d1->t - d2->t) ) |
119 |
< |
return(c); |
120 |
< |
return(d1->p - d2->p); |
118 |
> |
static void |
119 |
> |
trade_patchsamp(double ss[2]) /* trade in problem patch position */ |
120 |
> |
{ |
121 |
> |
static float excharr[XLOTSIZ][2]; |
122 |
> |
static short gterm[COTHER+1]; |
123 |
> |
double srep[2]; |
124 |
> |
int sclass, rclass; |
125 |
> |
int x; |
126 |
> |
/* reset on corner overload */ |
127 |
> |
if (gterm[COTHER-1] >= (CMAXTARGET+XLOTSIZ)/2) |
128 |
> |
memset(gterm, 0, sizeof(gterm)); |
129 |
> |
/* (re-)initialize? */ |
130 |
> |
while (gterm[COTHER] < XLOTSIZ) { |
131 |
> |
excharr[gterm[COTHER]][0] = frandom(); |
132 |
> |
excharr[gterm[COTHER]][1] = frandom(); |
133 |
> |
++gterm[COTHER]; |
134 |
> |
} /* get trade-in candidate... */ |
135 |
> |
sclass = psample_class(ss); /* submitted corner or not? */ |
136 |
> |
switch (sclass) { |
137 |
> |
case COTHER: /* trade mid-edge with corner/any */ |
138 |
> |
x = irandom( gterm[COTHER-1] > CMAXTARGET |
139 |
> |
? gterm[COTHER-1] : XLOTSIZ ); |
140 |
> |
break; |
141 |
> |
case CFIRST: /* kick out of first corner */ |
142 |
> |
x = gterm[CFIRST] + irandom(XLOTSIZ - gterm[CFIRST]); |
143 |
> |
break; |
144 |
> |
default: /* kick out of 2nd-4th corner */ |
145 |
> |
x = irandom(XLOTSIZ - (gterm[sclass] - gterm[sclass-1])); |
146 |
> |
x += (x >= gterm[sclass-1])*(gterm[sclass] - gterm[sclass-1]); |
147 |
> |
break; |
148 |
> |
} |
149 |
> |
srep[0] = excharr[x][0]; /* save selected trade output */ |
150 |
> |
srep[1] = excharr[x][1]; |
151 |
> |
/* adjust our lot groups */ |
152 |
> |
for (rclass = CFIRST; rclass < COTHER; rclass++) |
153 |
> |
if (x < gterm[rclass]) |
154 |
> |
break; |
155 |
> |
if (sclass < rclass) { /* submitted group before replacement? */ |
156 |
> |
CXCOPY(x, gterm[rclass-1]); |
157 |
> |
while (--rclass > sclass) { |
158 |
> |
CXCOPY(gterm[rclass], gterm[rclass-1]); |
159 |
> |
++gterm[rclass]; |
160 |
> |
} |
161 |
> |
x = gterm[sclass]++; |
162 |
> |
} else if (sclass > rclass) { /* submitted group after replacement? */ |
163 |
> |
--gterm[rclass]; |
164 |
> |
CXCOPY(x, gterm[rclass]); |
165 |
> |
while (++rclass < sclass) { |
166 |
> |
--gterm[rclass]; |
167 |
> |
CXCOPY(gterm[rclass-1], gterm[rclass]); |
168 |
> |
} |
169 |
> |
x = gterm[sclass-1]; |
170 |
> |
} |
171 |
> |
excharr[x][0] = ss[0]; /* complete the transaction */ |
172 |
> |
excharr[x][1] = ss[1]; |
173 |
> |
ss[0] = srep[0]; |
174 |
> |
ss[1] = srep[1]; |
175 |
|
} |
176 |
|
|
177 |
+ |
#undef CXCOPY |
178 |
+ |
#undef XLOTSIZ |
179 |
+ |
#undef COTHER |
180 |
+ |
#undef CFIRST |
181 |
|
|
43 |
– |
int |
44 |
– |
divsample(dp, h, r) /* sample a division */ |
45 |
– |
register AMBSAMP *dp; |
46 |
– |
AMBHEMI *h; |
47 |
– |
RAY *r; |
48 |
– |
{ |
49 |
– |
RAY ar; |
50 |
– |
int hlist[3]; |
51 |
– |
double spt[2]; |
52 |
– |
double xd, yd, zd; |
53 |
– |
double b2; |
54 |
– |
double phi; |
55 |
– |
register int i; |
182 |
|
|
183 |
< |
if (rayorigin(&ar, r, AMBIENT, AVGREFL) < 0) |
184 |
< |
return(-1); |
185 |
< |
hlist[0] = r->rno; |
186 |
< |
hlist[1] = dp->t; |
187 |
< |
hlist[2] = dp->p; |
188 |
< |
multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n)); |
189 |
< |
zd = sqrt((dp->t + spt[0])/h->nt); |
190 |
< |
phi = 2.0*PI * (dp->p + spt[1])/h->np; |
191 |
< |
xd = tcos(phi) * zd; |
192 |
< |
yd = tsin(phi) * zd; |
193 |
< |
zd = sqrt(1.0 - zd*zd); |
194 |
< |
for (i = 0; i < 3; i++) |
195 |
< |
ar.rdir[i] = xd*h->ux[i] + |
196 |
< |
yd*h->uy[i] + |
197 |
< |
zd*h->uz[i]; |
198 |
< |
dimlist[ndims++] = dp->t*h->np + dp->p + 90171; |
199 |
< |
rayvalue(&ar); |
183 |
> |
static int |
184 |
> |
ambsample( /* initial ambient division sample */ |
185 |
> |
AMBHEMI *hp, |
186 |
> |
int i, |
187 |
> |
int j, |
188 |
> |
int n |
189 |
> |
) |
190 |
> |
{ |
191 |
> |
AMBSAMP *ap = &ambsam(hp,i,j); |
192 |
> |
RAY ar; |
193 |
> |
int hlist[3], ii; |
194 |
> |
double ss[2]; |
195 |
> |
RREAL spt[2]; |
196 |
> |
double zd; |
197 |
> |
/* generate hemispherical sample */ |
198 |
> |
/* ambient coefficient for weight */ |
199 |
> |
if (ambacc > FTINY) |
200 |
> |
setscolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL); |
201 |
> |
else |
202 |
> |
copyscolor(ar.rcoef, hp->acoef); |
203 |
> |
if (rayorigin(&ar, hp->atyp, hp->rp, ar.rcoef) < 0) |
204 |
> |
return(0); |
205 |
> |
if (ambacc > FTINY) { |
206 |
> |
smultscolor(ar.rcoef, hp->acoef); |
207 |
> |
scalescolor(ar.rcoef, 1./AVGREFL); |
208 |
> |
} |
209 |
> |
hlist[0] = hp->rp->rno; |
210 |
> |
hlist[1] = AI(hp,i,j); |
211 |
> |
hlist[2] = samplendx; |
212 |
> |
multisamp(ss, 2, urand(ilhash(hlist,3)+n)); |
213 |
> |
patch_redo: |
214 |
> |
square2disk(spt, (j+ss[1])/hp->ns, (i+ss[0])/hp->ns); |
215 |
> |
zd = sqrt(1. - spt[0]*spt[0] - spt[1]*spt[1]); |
216 |
> |
for (ii = 3; ii--; ) |
217 |
> |
ar.rdir[ii] = spt[0]*hp->ux[ii] + |
218 |
> |
spt[1]*hp->uy[ii] + |
219 |
> |
zd*hp->onrm[ii]; |
220 |
> |
checknorm(ar.rdir); |
221 |
> |
/* avoid coincident samples */ |
222 |
> |
if (!n & (hp->ns >= 4) && ambcollision(hp, i, j, ar.rdir)) { |
223 |
> |
trade_patchsamp(ss); |
224 |
> |
goto patch_redo; |
225 |
> |
} |
226 |
> |
dimlist[ndims++] = AI(hp,i,j) + 90171; |
227 |
> |
rayvalue(&ar); /* evaluate ray */ |
228 |
|
ndims--; |
229 |
< |
addcolor(dp->v, ar.rcol); |
230 |
< |
/* use rt to improve gradient calc */ |
231 |
< |
if (ar.rt > FTINY && ar.rt < FHUGE) |
232 |
< |
dp->r += 1.0/ar.rt; |
233 |
< |
/* (re)initialize error */ |
234 |
< |
if (dp->n++) { |
235 |
< |
b2 = bright(dp->v)/dp->n - bright(ar.rcol); |
236 |
< |
b2 = b2*b2 + dp->k*((dp->n-1)*(dp->n-1)); |
237 |
< |
dp->k = b2/(dp->n*dp->n); |
238 |
< |
} else |
239 |
< |
dp->k = 0.0; |
240 |
< |
return(0); |
229 |
> |
zd = raydistance(&ar); |
230 |
> |
if (zd <= FTINY) |
231 |
> |
return(0); /* should never happen */ |
232 |
> |
smultscolor(ar.rcol, ar.rcoef); /* apply coefficient */ |
233 |
> |
if (zd*ap->d < 1.0) /* new/closer distance? */ |
234 |
> |
ap->d = 1.0/zd; |
235 |
> |
if (!n) { /* record first vertex & value */ |
236 |
> |
if (zd > 10.0*thescene.cusize + 1000.) |
237 |
> |
zd = 10.0*thescene.cusize + 1000.; |
238 |
> |
VSUM(ap->p, ar.rorg, ar.rdir, zd); |
239 |
> |
copyscolor(ap->v, ar.rcol); |
240 |
> |
} else { /* else update recorded value */ |
241 |
> |
sopscolor(hp->acol, -=, ap->v); |
242 |
> |
zd = 1.0/(double)(n+1); |
243 |
> |
scalescolor(ar.rcol, zd); |
244 |
> |
zd *= (double)n; |
245 |
> |
scalescolor(ap->v, zd); |
246 |
> |
saddscolor(ap->v, ar.rcol); |
247 |
> |
} |
248 |
> |
saddscolor(hp->acol, ap->v); /* add to our sum */ |
249 |
> |
return(1); |
250 |
|
} |
251 |
|
|
252 |
|
|
253 |
< |
double |
254 |
< |
doambient(acol, r, wt, pg, dg) /* compute ambient component */ |
255 |
< |
COLOR acol; |
93 |
< |
RAY *r; |
94 |
< |
double wt; |
95 |
< |
FVECT pg, dg; |
253 |
> |
/* Estimate variance based on ambient division differences */ |
254 |
> |
static float * |
255 |
> |
getambdiffs(AMBHEMI *hp) |
256 |
|
{ |
257 |
< |
double b, d; |
258 |
< |
AMBHEMI hemi; |
259 |
< |
AMBSAMP *div; |
260 |
< |
AMBSAMP dnew; |
261 |
< |
register AMBSAMP *dp; |
262 |
< |
double arad; |
263 |
< |
int ndivs, ns; |
264 |
< |
register int i, j; |
265 |
< |
/* initialize color */ |
266 |
< |
setcolor(acol, 0.0, 0.0, 0.0); |
267 |
< |
/* initialize hemisphere */ |
268 |
< |
inithemi(&hemi, r, wt); |
269 |
< |
ndivs = hemi.nt * hemi.np; |
270 |
< |
if (ndivs == 0) |
271 |
< |
return(0.0); |
272 |
< |
/* set number of super-samples */ |
273 |
< |
ns = ambssamp * wt + 0.5; |
274 |
< |
if (ns > 0 || pg != NULL || dg != NULL) { |
275 |
< |
div = (AMBSAMP *)malloc(ndivs*sizeof(AMBSAMP)); |
276 |
< |
if (div == NULL) |
277 |
< |
error(SYSTEM, "out of memory in doambient"); |
118 |
< |
} else |
119 |
< |
div = NULL; |
120 |
< |
/* sample the divisions */ |
121 |
< |
arad = 0.0; |
122 |
< |
if ((dp = div) == NULL) |
123 |
< |
dp = &dnew; |
124 |
< |
for (i = 0; i < hemi.nt; i++) |
125 |
< |
for (j = 0; j < hemi.np; j++) { |
126 |
< |
dp->t = i; dp->p = j; |
127 |
< |
setcolor(dp->v, 0.0, 0.0, 0.0); |
128 |
< |
dp->r = 0.0; |
129 |
< |
dp->n = 0; |
130 |
< |
if (divsample(dp, &hemi, r) < 0) |
131 |
< |
goto oopsy; |
132 |
< |
arad += dp->r; |
133 |
< |
if (div != NULL) |
134 |
< |
dp++; |
135 |
< |
else |
136 |
< |
addcolor(acol, dp->v); |
257 |
> |
const double normf = 1./(pbright(hp->acoef) + FTINY); |
258 |
> |
float *earr = (float *)calloc(2*hp->ns*hp->ns, sizeof(float)); |
259 |
> |
float *ep; |
260 |
> |
AMBSAMP *ap; |
261 |
> |
double b, b1, d2; |
262 |
> |
int i, j; |
263 |
> |
|
264 |
> |
if (earr == NULL) /* out of memory? */ |
265 |
> |
return(NULL); |
266 |
> |
/* sum squared neighbor diffs */ |
267 |
> |
ap = hp->sa; |
268 |
> |
ep = earr + hp->ns*hp->ns; /* original estimates to scratch */ |
269 |
> |
for (i = 0; i < hp->ns; i++) |
270 |
> |
for (j = 0; j < hp->ns; j++, ap++, ep++) { |
271 |
> |
b = pbright(ap[0].v); |
272 |
> |
if (i) { /* from above */ |
273 |
> |
b1 = pbright(ap[-hp->ns].v); |
274 |
> |
d2 = b - b1; |
275 |
> |
d2 *= d2*normf/(b + b1 + FTINY); |
276 |
> |
ep[0] += d2; |
277 |
> |
ep[-hp->ns] += d2; |
278 |
|
} |
279 |
< |
if (ns > 0 && arad > FTINY && ndivs/arad < minarad) |
280 |
< |
ns = 0; /* close enough */ |
281 |
< |
else if (ns > 0) { /* else perform super-sampling */ |
282 |
< |
comperrs(div, &hemi); /* compute errors */ |
283 |
< |
qsort(div, ndivs, sizeof(AMBSAMP), ambcmp); /* sort divs */ |
284 |
< |
/* super-sample */ |
285 |
< |
for (i = ns; i > 0; i--) { |
286 |
< |
dnew = *div; |
287 |
< |
if (divsample(&dnew, &hemi, r) < 0) |
288 |
< |
goto oopsy; |
289 |
< |
/* reinsert */ |
290 |
< |
dp = div; |
291 |
< |
j = ndivs < i ? ndivs : i; |
292 |
< |
while (--j > 0 && dnew.k < dp[1].k) { |
293 |
< |
*dp = *(dp+1); |
294 |
< |
dp++; |
295 |
< |
} |
296 |
< |
*dp = dnew; |
297 |
< |
} |
298 |
< |
if (pg != NULL || dg != NULL) /* restore order */ |
299 |
< |
qsort(div, ndivs, sizeof(AMBSAMP), ambnorm); |
279 |
> |
if (!j) continue; |
280 |
> |
/* from behind */ |
281 |
> |
b1 = pbright(ap[-1].v); |
282 |
> |
d2 = b - b1; |
283 |
> |
d2 *= d2*normf/(b + b1 + FTINY); |
284 |
> |
ep[0] += d2; |
285 |
> |
ep[-1] += d2; |
286 |
> |
if (!i) continue; |
287 |
> |
/* diagonal */ |
288 |
> |
b1 = pbright(ap[-hp->ns-1].v); |
289 |
> |
d2 = b - b1; |
290 |
> |
d2 *= d2*normf/(b + b1 + FTINY); |
291 |
> |
ep[0] += d2; |
292 |
> |
ep[-hp->ns-1] += d2; |
293 |
> |
} |
294 |
> |
/* correct for number of neighbors */ |
295 |
> |
ep = earr + hp->ns*hp->ns; |
296 |
> |
ep[0] *= 6./3.; |
297 |
> |
ep[hp->ns-1] *= 6./3.; |
298 |
> |
ep[(hp->ns-1)*hp->ns] *= 6./3.; |
299 |
> |
ep[(hp->ns-1)*hp->ns + hp->ns-1] *= 6./3.; |
300 |
> |
for (i = 1; i < hp->ns-1; i++) { |
301 |
> |
ep[i*hp->ns] *= 6./5.; |
302 |
> |
ep[i*hp->ns + hp->ns-1] *= 6./5.; |
303 |
|
} |
304 |
< |
/* compute returned values */ |
305 |
< |
if (div != NULL) { |
306 |
< |
arad = 0.0; |
163 |
< |
for (i = ndivs, dp = div; i-- > 0; dp++) { |
164 |
< |
arad += dp->r; |
165 |
< |
if (dp->n > 1) { |
166 |
< |
b = 1.0/dp->n; |
167 |
< |
scalecolor(dp->v, b); |
168 |
< |
dp->r *= b; |
169 |
< |
dp->n = 1; |
170 |
< |
} |
171 |
< |
addcolor(acol, dp->v); |
172 |
< |
} |
173 |
< |
b = bright(acol); |
174 |
< |
if (b > FTINY) { |
175 |
< |
b = ndivs/b; |
176 |
< |
if (pg != NULL) { |
177 |
< |
posgradient(pg, div, &hemi); |
178 |
< |
for (i = 0; i < 3; i++) |
179 |
< |
pg[i] *= b; |
180 |
< |
} |
181 |
< |
if (dg != NULL) { |
182 |
< |
dirgradient(dg, div, &hemi); |
183 |
< |
for (i = 0; i < 3; i++) |
184 |
< |
dg[i] *= b; |
185 |
< |
} |
186 |
< |
} else { |
187 |
< |
if (pg != NULL) |
188 |
< |
for (i = 0; i < 3; i++) |
189 |
< |
pg[i] = 0.0; |
190 |
< |
if (dg != NULL) |
191 |
< |
for (i = 0; i < 3; i++) |
192 |
< |
dg[i] = 0.0; |
193 |
< |
} |
194 |
< |
free((void *)div); |
304 |
> |
for (j = 1; j < hp->ns-1; j++) { |
305 |
> |
ep[j] *= 6./5.; |
306 |
> |
ep[(hp->ns-1)*hp->ns + j] *= 6./5.; |
307 |
|
} |
308 |
< |
b = 1.0/ndivs; |
309 |
< |
scalecolor(acol, b); |
310 |
< |
if (arad <= FTINY) |
311 |
< |
arad = maxarad; |
312 |
< |
else |
313 |
< |
arad = (ndivs+ns)/arad; |
314 |
< |
if (pg != NULL) { /* reduce radius if gradient large */ |
315 |
< |
d = DOT(pg,pg); |
316 |
< |
if (d*arad*arad > 1.0) |
317 |
< |
arad = 1.0/sqrt(d); |
308 |
> |
/* blur final map to reduce bias */ |
309 |
> |
for (i = 0; i < hp->ns-1; i++) { |
310 |
> |
float *ep2; |
311 |
> |
ep = earr + i*hp->ns; |
312 |
> |
ep2 = ep + hp->ns*hp->ns; |
313 |
> |
for (j = 0; j < hp->ns-1; j++, ep++, ep2++) { |
314 |
> |
ep[0] += .5*ep2[0] + .125*(ep2[1] + ep2[hp->ns]); |
315 |
> |
ep[1] += .125*ep2[0]; |
316 |
> |
ep[hp->ns] += .125*ep2[0]; |
317 |
> |
} |
318 |
|
} |
319 |
< |
if (arad < minarad) { |
320 |
< |
arad = minarad; |
321 |
< |
if (pg != NULL && d*arad*arad > 1.0) { /* cap gradient */ |
322 |
< |
d = 1.0/arad/sqrt(d); |
323 |
< |
for (i = 0; i < 3; i++) |
324 |
< |
pg[i] *= d; |
325 |
< |
} |
319 |
> |
return(earr); |
320 |
> |
} |
321 |
> |
|
322 |
> |
|
323 |
> |
/* Perform super-sampling on hemisphere (introduces bias) */ |
324 |
> |
static void |
325 |
> |
ambsupersamp(AMBHEMI *hp, int cnt) |
326 |
> |
{ |
327 |
> |
float *earr = getambdiffs(hp); |
328 |
> |
double e2rem = 0; |
329 |
> |
float *ep; |
330 |
> |
int i, j, n, nss; |
331 |
> |
|
332 |
> |
if (earr == NULL) /* just skip calc. if no memory */ |
333 |
> |
return; |
334 |
> |
/* accumulate estimated variances */ |
335 |
> |
for (ep = earr + hp->ns*hp->ns; ep > earr; ) |
336 |
> |
e2rem += *--ep; |
337 |
> |
ep = earr; /* perform super-sampling */ |
338 |
> |
for (i = 0; i < hp->ns; i++) |
339 |
> |
for (j = 0; j < hp->ns; j++) { |
340 |
> |
if (e2rem <= FTINY) |
341 |
> |
goto done; /* nothing left to do */ |
342 |
> |
nss = *ep/e2rem*cnt + frandom(); |
343 |
> |
for (n = 1; n <= nss && ambsample(hp,i,j,n); n++) |
344 |
> |
if (!--cnt) goto done; |
345 |
> |
e2rem -= *ep++; /* update remainder */ |
346 |
|
} |
347 |
< |
if ((arad /= sqrt(wt)) > maxarad) |
348 |
< |
arad = maxarad; |
217 |
< |
return(arad); |
218 |
< |
oopsy: |
219 |
< |
if (div != NULL) |
220 |
< |
free((void *)div); |
221 |
< |
return(0.0); |
347 |
> |
done: |
348 |
> |
free(earr); |
349 |
|
} |
350 |
|
|
351 |
|
|
352 |
< |
void |
353 |
< |
inithemi(hp, r, wt) /* initialize sampling hemisphere */ |
354 |
< |
register AMBHEMI *hp; |
355 |
< |
RAY *r; |
356 |
< |
double wt; |
352 |
> |
static AMBHEMI * |
353 |
> |
samp_hemi( /* sample indirect hemisphere */ |
354 |
> |
SCOLOR rcol, |
355 |
> |
RAY *r, |
356 |
> |
double wt |
357 |
> |
) |
358 |
|
{ |
359 |
< |
register int i; |
359 |
> |
int backside = (wt < 0); |
360 |
> |
AMBHEMI *hp; |
361 |
> |
double d; |
362 |
> |
int n, i, j; |
363 |
> |
/* insignificance check */ |
364 |
> |
d = sintens(rcol); |
365 |
> |
if (d <= FTINY) |
366 |
> |
return(NULL); |
367 |
|
/* set number of divisions */ |
368 |
< |
hp->nt = sqrt(ambdiv * wt / PI) + 0.5; |
369 |
< |
i = ambacc > FTINY ? 3 : 1; /* minimum number of samples */ |
370 |
< |
if (hp->nt < i) |
371 |
< |
hp->nt = i; |
372 |
< |
hp->np = PI * hp->nt + 0.5; |
373 |
< |
/* make axes */ |
374 |
< |
VCOPY(hp->uz, r->ron); |
375 |
< |
hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0; |
376 |
< |
for (i = 0; i < 3; i++) |
377 |
< |
if (hp->uz[i] < 0.6 && hp->uz[i] > -0.6) |
378 |
< |
break; |
379 |
< |
if (i >= 3) |
380 |
< |
error(CONSISTENCY, "bad ray direction in inithemi"); |
381 |
< |
hp->uy[i] = 1.0; |
382 |
< |
fcross(hp->ux, hp->uy, hp->uz); |
383 |
< |
normalize(hp->ux); |
384 |
< |
fcross(hp->uy, hp->uz, hp->ux); |
368 |
> |
if (backside) wt = -wt; |
369 |
> |
if (ambacc <= FTINY && |
370 |
> |
wt > (d *= 0.8*r->rweight/(ambdiv*minweight + 1e-20))) |
371 |
> |
wt = d; /* avoid ray termination */ |
372 |
> |
n = sqrt(ambdiv * wt) + 0.5; |
373 |
> |
i = 1 + (MINADIV-1)*(ambacc > FTINY); |
374 |
> |
if (n < i) /* use minimum number of samples? */ |
375 |
> |
n = i; |
376 |
> |
/* allocate sampling array */ |
377 |
> |
hp = (AMBHEMI *)malloc(sizeof(AMBHEMI) + sizeof(AMBSAMP)*(n*n - 1)); |
378 |
> |
if (hp == NULL) |
379 |
> |
error(SYSTEM, "out of memory in samp_hemi"); |
380 |
> |
|
381 |
> |
if (backside) { |
382 |
> |
hp->atyp = TAMBIENT; |
383 |
> |
hp->onrm[0] = -r->ron[0]; |
384 |
> |
hp->onrm[1] = -r->ron[1]; |
385 |
> |
hp->onrm[2] = -r->ron[2]; |
386 |
> |
} else { |
387 |
> |
hp->atyp = RAMBIENT; |
388 |
> |
VCOPY(hp->onrm, r->ron); |
389 |
> |
} |
390 |
> |
hp->rp = r; |
391 |
> |
hp->ns = n; |
392 |
> |
scolorblack(hp->acol); |
393 |
> |
memset(hp->sa, 0, sizeof(AMBSAMP)*n*n); |
394 |
> |
hp->sampOK = 0; |
395 |
> |
/* assign coefficient */ |
396 |
> |
copyscolor(hp->acoef, rcol); |
397 |
> |
d = 1.0/(n*n); |
398 |
> |
scalescolor(hp->acoef, d); |
399 |
> |
/* make tangent plane axes */ |
400 |
> |
if (!getperpendicular(hp->ux, hp->onrm, 1)) |
401 |
> |
error(CONSISTENCY, "bad ray direction in samp_hemi"); |
402 |
> |
VCROSS(hp->uy, hp->onrm, hp->ux); |
403 |
> |
/* sample divisions */ |
404 |
> |
for (i = hp->ns; i--; ) |
405 |
> |
for (j = hp->ns; j--; ) |
406 |
> |
hp->sampOK += ambsample(hp, i, j, 0); |
407 |
> |
copyscolor(rcol, hp->acol); |
408 |
> |
if (!hp->sampOK) { /* utter failure? */ |
409 |
> |
free(hp); |
410 |
> |
return(NULL); |
411 |
> |
} |
412 |
> |
if (hp->sampOK < hp->ns*hp->ns) { |
413 |
> |
hp->sampOK *= -1; /* soft failure */ |
414 |
> |
return(hp); |
415 |
> |
} |
416 |
> |
if (hp->sampOK <= MINADIV*MINADIV) |
417 |
> |
return(hp); /* don't bother super-sampling */ |
418 |
> |
n = ambssamp*wt + 0.5; |
419 |
> |
if (n >= 4*hp->ns) { /* perform super-sampling? */ |
420 |
> |
ambsupersamp(hp, n); |
421 |
> |
copyscolor(rcol, hp->acol); |
422 |
> |
} |
423 |
> |
return(hp); /* all is well */ |
424 |
|
} |
425 |
|
|
426 |
|
|
427 |
< |
void |
428 |
< |
comperrs(da, hp) /* compute initial error estimates */ |
429 |
< |
AMBSAMP *da; /* assumes standard ordering */ |
256 |
< |
register AMBHEMI *hp; |
427 |
> |
/* Return brightness of farthest ambient sample */ |
428 |
> |
static double |
429 |
> |
back_ambval(AMBHEMI *hp, const int n1, const int n2, const int n3) |
430 |
|
{ |
431 |
< |
double b, b2; |
432 |
< |
int i, j; |
433 |
< |
register AMBSAMP *dp; |
434 |
< |
/* sum differences from neighbors */ |
435 |
< |
dp = da; |
436 |
< |
for (i = 0; i < hp->nt; i++) |
437 |
< |
for (j = 0; j < hp->np; j++) { |
438 |
< |
#ifdef DEBUG |
266 |
< |
if (dp->t != i || dp->p != j) |
267 |
< |
error(CONSISTENCY, |
268 |
< |
"division order in comperrs"); |
269 |
< |
#endif |
270 |
< |
b = bright(dp[0].v); |
271 |
< |
if (i > 0) { /* from above */ |
272 |
< |
b2 = bright(dp[-hp->np].v) - b; |
273 |
< |
b2 *= b2 * 0.25; |
274 |
< |
dp[0].k += b2; |
275 |
< |
dp[-hp->np].k += b2; |
276 |
< |
} |
277 |
< |
if (j > 0) { /* from behind */ |
278 |
< |
b2 = bright(dp[-1].v) - b; |
279 |
< |
b2 *= b2 * 0.25; |
280 |
< |
dp[0].k += b2; |
281 |
< |
dp[-1].k += b2; |
282 |
< |
} else { /* around */ |
283 |
< |
b2 = bright(dp[hp->np-1].v) - b; |
284 |
< |
b2 *= b2 * 0.25; |
285 |
< |
dp[0].k += b2; |
286 |
< |
dp[hp->np-1].k += b2; |
287 |
< |
} |
288 |
< |
dp++; |
289 |
< |
} |
290 |
< |
/* divide by number of neighbors */ |
291 |
< |
dp = da; |
292 |
< |
for (j = 0; j < hp->np; j++) /* top row */ |
293 |
< |
(dp++)->k *= 1.0/3.0; |
294 |
< |
if (hp->nt < 2) |
295 |
< |
return; |
296 |
< |
for (i = 1; i < hp->nt-1; i++) /* central region */ |
297 |
< |
for (j = 0; j < hp->np; j++) |
298 |
< |
(dp++)->k *= 0.25; |
299 |
< |
for (j = 0; j < hp->np; j++) /* bottom row */ |
300 |
< |
(dp++)->k *= 1.0/3.0; |
431 |
> |
if (hp->sa[n1].d <= hp->sa[n2].d) { |
432 |
> |
if (hp->sa[n1].d <= hp->sa[n3].d) |
433 |
> |
return(hp->sa[n1].v[0]); |
434 |
> |
return(hp->sa[n3].v[0]); |
435 |
> |
} |
436 |
> |
if (hp->sa[n2].d <= hp->sa[n3].d) |
437 |
> |
return(hp->sa[n2].v[0]); |
438 |
> |
return(hp->sa[n3].v[0]); |
439 |
|
} |
440 |
|
|
441 |
|
|
442 |
< |
void |
443 |
< |
posgradient(gv, da, hp) /* compute position gradient */ |
444 |
< |
FVECT gv; |
307 |
< |
AMBSAMP *da; /* assumes standard ordering */ |
308 |
< |
register AMBHEMI *hp; |
442 |
> |
/* Compute vectors and coefficients for Hessian/gradient calcs */ |
443 |
> |
static void |
444 |
> |
comp_fftri(FFTRI *ftp, AMBHEMI *hp, const int n0, const int n1) |
445 |
|
{ |
446 |
< |
register int i, j; |
447 |
< |
double nextsine, lastsine, b, d; |
312 |
< |
double mag0, mag1; |
313 |
< |
double phi, cosp, sinp, xd, yd; |
314 |
< |
register AMBSAMP *dp; |
446 |
> |
double rdot_cp, dot_e, dot_er, rdot_r, rdot_r1, J2; |
447 |
> |
int ii; |
448 |
|
|
449 |
< |
xd = yd = 0.0; |
450 |
< |
for (j = 0; j < hp->np; j++) { |
451 |
< |
dp = da + j; |
452 |
< |
mag0 = mag1 = 0.0; |
453 |
< |
lastsine = 0.0; |
454 |
< |
for (i = 0; i < hp->nt; i++) { |
455 |
< |
#ifdef DEBUG |
456 |
< |
if (dp->t != i || dp->p != j) |
457 |
< |
error(CONSISTENCY, |
458 |
< |
"division order in posgradient"); |
459 |
< |
#endif |
460 |
< |
b = bright(dp->v); |
461 |
< |
if (i > 0) { |
462 |
< |
d = dp[-hp->np].r; |
463 |
< |
if (dp[0].r > d) d = dp[0].r; |
464 |
< |
/* sin(t)*cos(t)^2 */ |
465 |
< |
d *= lastsine * (1.0 - (double)i/hp->nt); |
466 |
< |
mag0 += d*(b - bright(dp[-hp->np].v)); |
467 |
< |
} |
468 |
< |
nextsine = sqrt((double)(i+1)/hp->nt); |
469 |
< |
if (j > 0) { |
470 |
< |
d = dp[-1].r; |
471 |
< |
if (dp[0].r > d) d = dp[0].r; |
472 |
< |
mag1 += d * (nextsine - lastsine) * |
473 |
< |
(b - bright(dp[-1].v)); |
474 |
< |
} else { |
475 |
< |
d = dp[hp->np-1].r; |
476 |
< |
if (dp[0].r > d) d = dp[0].r; |
477 |
< |
mag1 += d * (nextsine - lastsine) * |
478 |
< |
(b - bright(dp[hp->np-1].v)); |
479 |
< |
} |
480 |
< |
dp += hp->np; |
481 |
< |
lastsine = nextsine; |
449 |
> |
VSUB(ftp->r_i, hp->sa[n0].p, hp->rp->rop); |
450 |
> |
VSUB(ftp->r_i1, hp->sa[n1].p, hp->rp->rop); |
451 |
> |
VSUB(ftp->e_i, hp->sa[n1].p, hp->sa[n0].p); |
452 |
> |
VCROSS(ftp->rcp, ftp->r_i, ftp->r_i1); |
453 |
> |
rdot_cp = 1.0/DOT(ftp->rcp,ftp->rcp); |
454 |
> |
dot_e = DOT(ftp->e_i,ftp->e_i); |
455 |
> |
dot_er = DOT(ftp->e_i, ftp->r_i); |
456 |
> |
rdot_r = 1.0/DOT(ftp->r_i,ftp->r_i); |
457 |
> |
rdot_r1 = 1.0/DOT(ftp->r_i1,ftp->r_i1); |
458 |
> |
ftp->I1 = acos( DOT(ftp->r_i, ftp->r_i1) * sqrt(rdot_r*rdot_r1) ) * |
459 |
> |
sqrt( rdot_cp ); |
460 |
> |
ftp->I2 = ( DOT(ftp->e_i, ftp->r_i1)*rdot_r1 - dot_er*rdot_r + |
461 |
> |
dot_e*ftp->I1 )*0.5*rdot_cp; |
462 |
> |
J2 = ( 0.5*(rdot_r - rdot_r1) - dot_er*ftp->I2 ) / dot_e; |
463 |
> |
for (ii = 3; ii--; ) |
464 |
> |
ftp->rI2_eJ2[ii] = ftp->I2*ftp->r_i[ii] + J2*ftp->e_i[ii]; |
465 |
> |
} |
466 |
> |
|
467 |
> |
|
468 |
> |
/* Compose 3x3 matrix from two vectors */ |
469 |
> |
static void |
470 |
> |
compose_matrix(FVECT mat[3], FVECT va, FVECT vb) |
471 |
> |
{ |
472 |
> |
mat[0][0] = 2.0*va[0]*vb[0]; |
473 |
> |
mat[1][1] = 2.0*va[1]*vb[1]; |
474 |
> |
mat[2][2] = 2.0*va[2]*vb[2]; |
475 |
> |
mat[0][1] = mat[1][0] = va[0]*vb[1] + va[1]*vb[0]; |
476 |
> |
mat[0][2] = mat[2][0] = va[0]*vb[2] + va[2]*vb[0]; |
477 |
> |
mat[1][2] = mat[2][1] = va[1]*vb[2] + va[2]*vb[1]; |
478 |
> |
} |
479 |
> |
|
480 |
> |
|
481 |
> |
/* Compute partial 3x3 Hessian matrix for edge */ |
482 |
> |
static void |
483 |
> |
comp_hessian(FVECT hess[3], FFTRI *ftp, FVECT nrm) |
484 |
> |
{ |
485 |
> |
FVECT ncp; |
486 |
> |
FVECT m1[3], m2[3], m3[3], m4[3]; |
487 |
> |
double d1, d2, d3, d4; |
488 |
> |
double I3, J3, K3; |
489 |
> |
int i, j; |
490 |
> |
/* compute intermediate coefficients */ |
491 |
> |
d1 = 1.0/DOT(ftp->r_i,ftp->r_i); |
492 |
> |
d2 = 1.0/DOT(ftp->r_i1,ftp->r_i1); |
493 |
> |
d3 = 1.0/DOT(ftp->e_i,ftp->e_i); |
494 |
> |
d4 = DOT(ftp->e_i, ftp->r_i); |
495 |
> |
I3 = ( DOT(ftp->e_i, ftp->r_i1)*d2*d2 - d4*d1*d1 + 3.0/d3*ftp->I2 ) |
496 |
> |
/ ( 4.0*DOT(ftp->rcp,ftp->rcp) ); |
497 |
> |
J3 = 0.25*d3*(d1*d1 - d2*d2) - d4*d3*I3; |
498 |
> |
K3 = d3*(ftp->I2 - I3/d1 - 2.0*d4*J3); |
499 |
> |
/* intermediate matrices */ |
500 |
> |
VCROSS(ncp, nrm, ftp->e_i); |
501 |
> |
compose_matrix(m1, ncp, ftp->rI2_eJ2); |
502 |
> |
compose_matrix(m2, ftp->r_i, ftp->r_i); |
503 |
> |
compose_matrix(m3, ftp->e_i, ftp->e_i); |
504 |
> |
compose_matrix(m4, ftp->r_i, ftp->e_i); |
505 |
> |
d1 = DOT(nrm, ftp->rcp); |
506 |
> |
d2 = -d1*ftp->I2; |
507 |
> |
d1 *= 2.0; |
508 |
> |
for (i = 3; i--; ) /* final matrix sum */ |
509 |
> |
for (j = 3; j--; ) { |
510 |
> |
hess[i][j] = m1[i][j] + d1*( I3*m2[i][j] + K3*m3[i][j] + |
511 |
> |
2.0*J3*m4[i][j] ); |
512 |
> |
hess[i][j] += d2*(i==j); |
513 |
> |
hess[i][j] *= -1.0/PI; |
514 |
> |
} |
515 |
> |
} |
516 |
> |
|
517 |
> |
|
518 |
> |
/* Reverse hessian calculation result for edge in other direction */ |
519 |
> |
static void |
520 |
> |
rev_hessian(FVECT hess[3]) |
521 |
> |
{ |
522 |
> |
int i; |
523 |
> |
|
524 |
> |
for (i = 3; i--; ) { |
525 |
> |
hess[i][0] = -hess[i][0]; |
526 |
> |
hess[i][1] = -hess[i][1]; |
527 |
> |
hess[i][2] = -hess[i][2]; |
528 |
> |
} |
529 |
> |
} |
530 |
> |
|
531 |
> |
|
532 |
> |
/* Add to radiometric Hessian from the given triangle */ |
533 |
> |
static void |
534 |
> |
add2hessian(FVECT hess[3], FVECT ehess1[3], |
535 |
> |
FVECT ehess2[3], FVECT ehess3[3], double v) |
536 |
> |
{ |
537 |
> |
int i, j; |
538 |
> |
|
539 |
> |
for (i = 3; i--; ) |
540 |
> |
for (j = 3; j--; ) |
541 |
> |
hess[i][j] += v*( ehess1[i][j] + ehess2[i][j] + ehess3[i][j] ); |
542 |
> |
} |
543 |
> |
|
544 |
> |
|
545 |
> |
/* Compute partial displacement form factor gradient for edge */ |
546 |
> |
static void |
547 |
> |
comp_gradient(FVECT grad, FFTRI *ftp, FVECT nrm) |
548 |
> |
{ |
549 |
> |
FVECT ncp; |
550 |
> |
double f1; |
551 |
> |
int i; |
552 |
> |
|
553 |
> |
f1 = 2.0*DOT(nrm, ftp->rcp); |
554 |
> |
VCROSS(ncp, nrm, ftp->e_i); |
555 |
> |
for (i = 3; i--; ) |
556 |
> |
grad[i] = (0.5/PI)*( ftp->I1*ncp[i] + f1*ftp->rI2_eJ2[i] ); |
557 |
> |
} |
558 |
> |
|
559 |
> |
|
560 |
> |
/* Reverse gradient calculation result for edge in other direction */ |
561 |
> |
static void |
562 |
> |
rev_gradient(FVECT grad) |
563 |
> |
{ |
564 |
> |
grad[0] = -grad[0]; |
565 |
> |
grad[1] = -grad[1]; |
566 |
> |
grad[2] = -grad[2]; |
567 |
> |
} |
568 |
> |
|
569 |
> |
|
570 |
> |
/* Add to displacement gradient from the given triangle */ |
571 |
> |
static void |
572 |
> |
add2gradient(FVECT grad, FVECT egrad1, FVECT egrad2, FVECT egrad3, double v) |
573 |
> |
{ |
574 |
> |
int i; |
575 |
> |
|
576 |
> |
for (i = 3; i--; ) |
577 |
> |
grad[i] += v*( egrad1[i] + egrad2[i] + egrad3[i] ); |
578 |
> |
} |
579 |
> |
|
580 |
> |
|
581 |
> |
/* Compute anisotropic radii and eigenvector directions */ |
582 |
> |
static void |
583 |
> |
eigenvectors(FVECT uv[2], float ra[2], FVECT hessian[3]) |
584 |
> |
{ |
585 |
> |
double hess2[2][2]; |
586 |
> |
FVECT a, b; |
587 |
> |
double evalue[2], slope1, xmag1; |
588 |
> |
int i; |
589 |
> |
/* project Hessian to sample plane */ |
590 |
> |
for (i = 3; i--; ) { |
591 |
> |
a[i] = DOT(hessian[i], uv[0]); |
592 |
> |
b[i] = DOT(hessian[i], uv[1]); |
593 |
> |
} |
594 |
> |
hess2[0][0] = DOT(uv[0], a); |
595 |
> |
hess2[0][1] = DOT(uv[0], b); |
596 |
> |
hess2[1][0] = DOT(uv[1], a); |
597 |
> |
hess2[1][1] = DOT(uv[1], b); |
598 |
> |
/* compute eigenvalue(s) */ |
599 |
> |
i = quadratic(evalue, 1.0, -hess2[0][0]-hess2[1][1], |
600 |
> |
hess2[0][0]*hess2[1][1]-hess2[0][1]*hess2[1][0]); |
601 |
> |
if (i == 1) /* double-root (circle) */ |
602 |
> |
evalue[1] = evalue[0]; |
603 |
> |
if (!i || ((evalue[0] = fabs(evalue[0])) <= FTINY*FTINY) | |
604 |
> |
((evalue[1] = fabs(evalue[1])) <= FTINY*FTINY) ) { |
605 |
> |
ra[0] = ra[1] = maxarad; |
606 |
> |
return; |
607 |
> |
} |
608 |
> |
if (evalue[0] > evalue[1]) { |
609 |
> |
ra[0] = sqrt(sqrt(4.0/evalue[0])); |
610 |
> |
ra[1] = sqrt(sqrt(4.0/evalue[1])); |
611 |
> |
slope1 = evalue[1]; |
612 |
> |
} else { |
613 |
> |
ra[0] = sqrt(sqrt(4.0/evalue[1])); |
614 |
> |
ra[1] = sqrt(sqrt(4.0/evalue[0])); |
615 |
> |
slope1 = evalue[0]; |
616 |
> |
} |
617 |
> |
/* compute unit eigenvectors */ |
618 |
> |
if (fabs(hess2[0][1]) <= FTINY) |
619 |
> |
return; /* uv OK as is */ |
620 |
> |
slope1 = (slope1 - hess2[0][0]) / hess2[0][1]; |
621 |
> |
xmag1 = sqrt(1.0/(1.0 + slope1*slope1)); |
622 |
> |
for (i = 3; i--; ) { |
623 |
> |
b[i] = xmag1*uv[0][i] + slope1*xmag1*uv[1][i]; |
624 |
> |
a[i] = slope1*xmag1*uv[0][i] - xmag1*uv[1][i]; |
625 |
> |
} |
626 |
> |
VCOPY(uv[0], a); |
627 |
> |
VCOPY(uv[1], b); |
628 |
> |
} |
629 |
> |
|
630 |
> |
|
631 |
> |
static void |
632 |
> |
ambHessian( /* anisotropic radii & pos. gradient */ |
633 |
> |
AMBHEMI *hp, |
634 |
> |
FVECT uv[2], /* returned */ |
635 |
> |
float ra[2], /* returned (optional) */ |
636 |
> |
float pg[2] /* returned (optional) */ |
637 |
> |
) |
638 |
> |
{ |
639 |
> |
static char memerrmsg[] = "out of memory in ambHessian()"; |
640 |
> |
FVECT (*hessrow)[3] = NULL; |
641 |
> |
FVECT *gradrow = NULL; |
642 |
> |
FVECT hessian[3]; |
643 |
> |
FVECT gradient; |
644 |
> |
FFTRI fftr; |
645 |
> |
int i, j; |
646 |
> |
/* be sure to assign unit vectors */ |
647 |
> |
VCOPY(uv[0], hp->ux); |
648 |
> |
VCOPY(uv[1], hp->uy); |
649 |
> |
/* clock-wise vertex traversal from sample POV */ |
650 |
> |
if (ra != NULL) { /* initialize Hessian row buffer */ |
651 |
> |
hessrow = (FVECT (*)[3])malloc(sizeof(FVECT)*3*(hp->ns-1)); |
652 |
> |
if (hessrow == NULL) |
653 |
> |
error(SYSTEM, memerrmsg); |
654 |
> |
memset(hessian, 0, sizeof(hessian)); |
655 |
> |
} else if (pg == NULL) /* bogus call? */ |
656 |
> |
return; |
657 |
> |
if (pg != NULL) { /* initialize form factor row buffer */ |
658 |
> |
gradrow = (FVECT *)malloc(sizeof(FVECT)*(hp->ns-1)); |
659 |
> |
if (gradrow == NULL) |
660 |
> |
error(SYSTEM, memerrmsg); |
661 |
> |
memset(gradient, 0, sizeof(gradient)); |
662 |
> |
} |
663 |
> |
/* compute first row of edges */ |
664 |
> |
for (j = 0; j < hp->ns-1; j++) { |
665 |
> |
comp_fftri(&fftr, hp, AI(hp,0,j), AI(hp,0,j+1)); |
666 |
> |
if (hessrow != NULL) |
667 |
> |
comp_hessian(hessrow[j], &fftr, hp->onrm); |
668 |
> |
if (gradrow != NULL) |
669 |
> |
comp_gradient(gradrow[j], &fftr, hp->onrm); |
670 |
> |
} |
671 |
> |
/* sum each row of triangles */ |
672 |
> |
for (i = 0; i < hp->ns-1; i++) { |
673 |
> |
FVECT hesscol[3]; /* compute first vertical edge */ |
674 |
> |
FVECT gradcol; |
675 |
> |
comp_fftri(&fftr, hp, AI(hp,i,0), AI(hp,i+1,0)); |
676 |
> |
if (hessrow != NULL) |
677 |
> |
comp_hessian(hesscol, &fftr, hp->onrm); |
678 |
> |
if (gradrow != NULL) |
679 |
> |
comp_gradient(gradcol, &fftr, hp->onrm); |
680 |
> |
for (j = 0; j < hp->ns-1; j++) { |
681 |
> |
FVECT hessdia[3]; /* compute triangle contributions */ |
682 |
> |
FVECT graddia; |
683 |
> |
double backg; |
684 |
> |
backg = back_ambval(hp, AI(hp,i,j), |
685 |
> |
AI(hp,i,j+1), AI(hp,i+1,j)); |
686 |
> |
/* diagonal (inner) edge */ |
687 |
> |
comp_fftri(&fftr, hp, AI(hp,i,j+1), AI(hp,i+1,j)); |
688 |
> |
if (hessrow != NULL) { |
689 |
> |
comp_hessian(hessdia, &fftr, hp->onrm); |
690 |
> |
rev_hessian(hesscol); |
691 |
> |
add2hessian(hessian, hessrow[j], hessdia, hesscol, backg); |
692 |
|
} |
693 |
< |
mag0 *= 2.0*PI / hp->np; |
694 |
< |
phi = 2.0*PI * (double)j/hp->np; |
695 |
< |
cosp = tcos(phi); sinp = tsin(phi); |
696 |
< |
xd += mag0*cosp - mag1*sinp; |
697 |
< |
yd += mag0*sinp + mag1*cosp; |
693 |
> |
if (gradrow != NULL) { |
694 |
> |
comp_gradient(graddia, &fftr, hp->onrm); |
695 |
> |
rev_gradient(gradcol); |
696 |
> |
add2gradient(gradient, gradrow[j], graddia, gradcol, backg); |
697 |
> |
} |
698 |
> |
/* initialize edge in next row */ |
699 |
> |
comp_fftri(&fftr, hp, AI(hp,i+1,j+1), AI(hp,i+1,j)); |
700 |
> |
if (hessrow != NULL) |
701 |
> |
comp_hessian(hessrow[j], &fftr, hp->onrm); |
702 |
> |
if (gradrow != NULL) |
703 |
> |
comp_gradient(gradrow[j], &fftr, hp->onrm); |
704 |
> |
/* new column edge & paired triangle */ |
705 |
> |
backg = back_ambval(hp, AI(hp,i+1,j+1), |
706 |
> |
AI(hp,i+1,j), AI(hp,i,j+1)); |
707 |
> |
comp_fftri(&fftr, hp, AI(hp,i,j+1), AI(hp,i+1,j+1)); |
708 |
> |
if (hessrow != NULL) { |
709 |
> |
comp_hessian(hesscol, &fftr, hp->onrm); |
710 |
> |
rev_hessian(hessdia); |
711 |
> |
add2hessian(hessian, hessrow[j], hessdia, hesscol, backg); |
712 |
> |
if (i < hp->ns-2) |
713 |
> |
rev_hessian(hessrow[j]); |
714 |
> |
} |
715 |
> |
if (gradrow != NULL) { |
716 |
> |
comp_gradient(gradcol, &fftr, hp->onrm); |
717 |
> |
rev_gradient(graddia); |
718 |
> |
add2gradient(gradient, gradrow[j], graddia, gradcol, backg); |
719 |
> |
if (i < hp->ns-2) |
720 |
> |
rev_gradient(gradrow[j]); |
721 |
> |
} |
722 |
> |
} |
723 |
|
} |
724 |
< |
for (i = 0; i < 3; i++) |
725 |
< |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/PI; |
724 |
> |
/* release row buffers */ |
725 |
> |
if (hessrow != NULL) free(hessrow); |
726 |
> |
if (gradrow != NULL) free(gradrow); |
727 |
> |
|
728 |
> |
if (ra != NULL) /* extract eigenvectors & radii */ |
729 |
> |
eigenvectors(uv, ra, hessian); |
730 |
> |
if (pg != NULL) { /* tangential position gradient */ |
731 |
> |
pg[0] = DOT(gradient, uv[0]); |
732 |
> |
pg[1] = DOT(gradient, uv[1]); |
733 |
> |
} |
734 |
|
} |
735 |
|
|
736 |
|
|
737 |
< |
void |
738 |
< |
dirgradient(gv, da, hp) /* compute direction gradient */ |
739 |
< |
FVECT gv; |
364 |
< |
AMBSAMP *da; /* assumes standard ordering */ |
365 |
< |
register AMBHEMI *hp; |
737 |
> |
/* Compute direction gradient from a hemispherical sampling */ |
738 |
> |
static void |
739 |
> |
ambdirgrad(AMBHEMI *hp, FVECT uv[2], float dg[2]) |
740 |
|
{ |
741 |
< |
register int i, j; |
742 |
< |
double mag; |
743 |
< |
double phi, xd, yd; |
744 |
< |
register AMBSAMP *dp; |
741 |
> |
AMBSAMP *ap; |
742 |
> |
double dgsum[2]; |
743 |
> |
int n; |
744 |
> |
FVECT vd; |
745 |
> |
double gfact; |
746 |
|
|
747 |
< |
xd = yd = 0.0; |
748 |
< |
for (j = 0; j < hp->np; j++) { |
749 |
< |
dp = da + j; |
750 |
< |
mag = 0.0; |
751 |
< |
for (i = 0; i < hp->nt; i++) { |
752 |
< |
#ifdef DEBUG |
753 |
< |
if (dp->t != i || dp->p != j) |
754 |
< |
error(CONSISTENCY, |
755 |
< |
"division order in dirgradient"); |
756 |
< |
#endif |
757 |
< |
/* tan(t) */ |
758 |
< |
mag += bright(dp->v)/sqrt(hp->nt/(i+.5) - 1.0); |
759 |
< |
dp += hp->np; |
747 |
> |
dgsum[0] = dgsum[1] = 0.0; /* sum values times -tan(theta) */ |
748 |
> |
for (ap = hp->sa, n = hp->ns*hp->ns; n--; ap++) { |
749 |
> |
/* use vector for azimuth + 90deg */ |
750 |
> |
VSUB(vd, ap->p, hp->rp->rop); |
751 |
> |
/* brightness over cosine factor */ |
752 |
> |
gfact = ap->v[0] / DOT(hp->onrm, vd); |
753 |
> |
/* sine = proj_radius/vd_length */ |
754 |
> |
dgsum[0] -= DOT(uv[1], vd) * gfact; |
755 |
> |
dgsum[1] += DOT(uv[0], vd) * gfact; |
756 |
> |
} |
757 |
> |
dg[0] = dgsum[0] / (hp->ns*hp->ns); |
758 |
> |
dg[1] = dgsum[1] / (hp->ns*hp->ns); |
759 |
> |
} |
760 |
> |
|
761 |
> |
|
762 |
> |
/* Compute potential light leak direction flags for cache value */ |
763 |
> |
static uint32 |
764 |
> |
ambcorral(AMBHEMI *hp, FVECT uv[2], const double r0, const double r1) |
765 |
> |
{ |
766 |
> |
const double max_d = 1.0/(minarad*ambacc + 0.001); |
767 |
> |
const double ang_res = 0.5*PI/hp->ns; |
768 |
> |
const double ang_step = ang_res/((int)(16/PI*ang_res) + 1.01); |
769 |
> |
double avg_d = 0; |
770 |
> |
uint32 flgs = 0; |
771 |
> |
FVECT vec; |
772 |
> |
double u, v; |
773 |
> |
double ang, a1; |
774 |
> |
int i, j; |
775 |
> |
/* don't bother for a few samples */ |
776 |
> |
if (hp->ns < 8) |
777 |
> |
return(0); |
778 |
> |
/* check distances overhead */ |
779 |
> |
for (i = hp->ns*3/4; i-- > hp->ns>>2; ) |
780 |
> |
for (j = hp->ns*3/4; j-- > hp->ns>>2; ) |
781 |
> |
avg_d += ambsam(hp,i,j).d; |
782 |
> |
avg_d *= 4.0/(hp->ns*hp->ns); |
783 |
> |
if (avg_d*r0 >= 1.0) /* ceiling too low for corral? */ |
784 |
> |
return(0); |
785 |
> |
if (avg_d >= max_d) /* insurance */ |
786 |
> |
return(0); |
787 |
> |
/* else circle around perimeter */ |
788 |
> |
for (i = 0; i < hp->ns; i++) |
789 |
> |
for (j = 0; j < hp->ns; j += !i|(i==hp->ns-1) ? 1 : hp->ns-1) { |
790 |
> |
AMBSAMP *ap = &ambsam(hp,i,j); |
791 |
> |
if ((ap->d <= FTINY) | (ap->d >= max_d)) |
792 |
> |
continue; /* too far or too near */ |
793 |
> |
VSUB(vec, ap->p, hp->rp->rop); |
794 |
> |
u = DOT(vec, uv[0]); |
795 |
> |
v = DOT(vec, uv[1]); |
796 |
> |
if ((r0*r0*u*u + r1*r1*v*v) * ap->d*ap->d <= u*u + v*v) |
797 |
> |
continue; /* occluder outside ellipse */ |
798 |
> |
ang = atan2a(v, u); /* else set direction flags */ |
799 |
> |
for (a1 = ang-ang_res; a1 <= ang+ang_res; a1 += ang_step) |
800 |
> |
flgs |= 1L<<(int)(16/PI*(a1 + 2.*PI*(a1 < 0))); |
801 |
> |
} |
802 |
> |
return(flgs); |
803 |
> |
} |
804 |
> |
|
805 |
> |
|
806 |
> |
int |
807 |
> |
doambient( /* compute ambient component */ |
808 |
> |
SCOLOR rcol, /* input/output color */ |
809 |
> |
RAY *r, |
810 |
> |
double wt, /* negative for back side */ |
811 |
> |
FVECT uv[2], /* returned (optional) */ |
812 |
> |
float ra[2], /* returned (optional) */ |
813 |
> |
float pg[2], /* returned (optional) */ |
814 |
> |
float dg[2], /* returned (optional) */ |
815 |
> |
uint32 *crlp /* returned (optional) */ |
816 |
> |
) |
817 |
> |
{ |
818 |
> |
AMBHEMI *hp = samp_hemi(rcol, r, wt); |
819 |
> |
FVECT my_uv[2]; |
820 |
> |
double d, K; |
821 |
> |
AMBSAMP *ap; |
822 |
> |
int i; |
823 |
> |
/* clear return values */ |
824 |
> |
if (uv != NULL) |
825 |
> |
memset(uv, 0, sizeof(FVECT)*2); |
826 |
> |
if (ra != NULL) |
827 |
> |
ra[0] = ra[1] = 0.0; |
828 |
> |
if (pg != NULL) |
829 |
> |
pg[0] = pg[1] = 0.0; |
830 |
> |
if (dg != NULL) |
831 |
> |
dg[0] = dg[1] = 0.0; |
832 |
> |
if (crlp != NULL) |
833 |
> |
*crlp = 0; |
834 |
> |
if (hp == NULL) /* sampling falure? */ |
835 |
> |
return(0); |
836 |
> |
|
837 |
> |
if ((ra == NULL) & (pg == NULL) & (dg == NULL) || |
838 |
> |
(hp->sampOK < 0) | (hp->ns < MINADIV)) { |
839 |
> |
free(hp); /* Hessian not requested/possible */ |
840 |
> |
return(-1); /* value-only return value */ |
841 |
> |
} |
842 |
> |
if ((d = scolor_mean(rcol)) > FTINY) { |
843 |
> |
d = 0.99*(hp->ns*hp->ns)/d; /* normalize avg. values */ |
844 |
> |
K = 0.01; |
845 |
> |
} else { /* or fall back on geometric Hessian */ |
846 |
> |
K = 1.0; |
847 |
> |
pg = NULL; |
848 |
> |
dg = NULL; |
849 |
> |
crlp = NULL; |
850 |
> |
} |
851 |
> |
ap = hp->sa; /* single channel from here on... */ |
852 |
> |
for (i = hp->ns*hp->ns; i--; ap++) |
853 |
> |
ap->v[0] = scolor_mean(ap->v)*d + K; |
854 |
> |
|
855 |
> |
if (uv == NULL) /* make sure we have axis pointers */ |
856 |
> |
uv = my_uv; |
857 |
> |
/* compute radii & pos. gradient */ |
858 |
> |
ambHessian(hp, uv, ra, pg); |
859 |
> |
|
860 |
> |
if (dg != NULL) /* compute direction gradient */ |
861 |
> |
ambdirgrad(hp, uv, dg); |
862 |
> |
|
863 |
> |
if (ra != NULL) { /* scale/clamp radii */ |
864 |
> |
if (pg != NULL) { |
865 |
> |
if (ra[0]*(d = fabs(pg[0])) > 1.0) |
866 |
> |
ra[0] = 1.0/d; |
867 |
> |
if (ra[1]*(d = fabs(pg[1])) > 1.0) |
868 |
> |
ra[1] = 1.0/d; |
869 |
> |
if (ra[0] > ra[1]) |
870 |
> |
ra[0] = ra[1]; |
871 |
|
} |
872 |
< |
phi = 2.0*PI * (j+.5)/hp->np + PI/2.0; |
873 |
< |
xd += mag * tcos(phi); |
874 |
< |
yd += mag * tsin(phi); |
872 |
> |
if (ra[0] < minarad) { |
873 |
> |
ra[0] = minarad; |
874 |
> |
if (ra[1] < minarad) |
875 |
> |
ra[1] = minarad; |
876 |
> |
} |
877 |
> |
ra[0] *= d = 1.0/sqrt(fabs(wt)); |
878 |
> |
if ((ra[1] *= d) > 2.0*ra[0]) |
879 |
> |
ra[1] = 2.0*ra[0]; |
880 |
> |
if (ra[1] > maxarad) { |
881 |
> |
ra[1] = maxarad; |
882 |
> |
if (ra[0] > maxarad) |
883 |
> |
ra[0] = maxarad; |
884 |
> |
} |
885 |
> |
/* flag encroached directions */ |
886 |
> |
if (crlp != NULL) /* XXX doesn't update with changes to ambacc */ |
887 |
> |
*crlp = ambcorral(hp, uv, ra[0]*ambacc, ra[1]*ambacc); |
888 |
> |
if (pg != NULL) { /* cap gradient if necessary */ |
889 |
> |
d = pg[0]*pg[0]*ra[0]*ra[0] + pg[1]*pg[1]*ra[1]*ra[1]; |
890 |
> |
if (d > 1.0) { |
891 |
> |
d = 1.0/sqrt(d); |
892 |
> |
pg[0] *= d; |
893 |
> |
pg[1] *= d; |
894 |
> |
} |
895 |
> |
} |
896 |
|
} |
897 |
< |
for (i = 0; i < 3; i++) |
898 |
< |
gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/(hp->nt*hp->np); |
897 |
> |
free(hp); /* clean up and return */ |
898 |
> |
return(1); |
899 |
|
} |