51 |
|
|
52 |
|
|
53 |
|
static int |
54 |
+ |
ambcollision( /* proposed direciton collides? */ |
55 |
+ |
AMBHEMI *hp, |
56 |
+ |
int i, |
57 |
+ |
int j, |
58 |
+ |
FVECT dv |
59 |
+ |
) |
60 |
+ |
{ |
61 |
+ |
double cos_thresh; |
62 |
+ |
int ii, jj; |
63 |
+ |
/* min. spacing = 1/10th division */ |
64 |
+ |
cos_thresh = (PI/10.)/(double)hp->ns; |
65 |
+ |
cos_thresh = 1. - .5*cos_thresh*cos_thresh; |
66 |
+ |
/* check existing neighbors */ |
67 |
+ |
for (ii = i-1; ii <= i+1; ii++) { |
68 |
+ |
if (ii < 0) continue; |
69 |
+ |
if (ii >= hp->ns) break; |
70 |
+ |
for (jj = j-1; jj <= j+1; jj++) { |
71 |
+ |
AMBSAMP *ap; |
72 |
+ |
FVECT avec; |
73 |
+ |
double dprod; |
74 |
+ |
if (jj < 0) continue; |
75 |
+ |
if (jj >= hp->ns) break; |
76 |
+ |
if ((ii==i) & (jj==j)) continue; |
77 |
+ |
ap = &ambsam(hp,ii,jj); |
78 |
+ |
if (ap->d <= .5/FHUGE) |
79 |
+ |
continue; /* no one home */ |
80 |
+ |
VSUB(avec, ap->p, hp->rp->rop); |
81 |
+ |
dprod = DOT(avec, dv); |
82 |
+ |
if (dprod >= cos_thresh*VLEN(avec)) |
83 |
+ |
return(1); /* collision */ |
84 |
+ |
} |
85 |
+ |
} |
86 |
+ |
return(0); /* nothing to worry about */ |
87 |
+ |
} |
88 |
+ |
|
89 |
+ |
|
90 |
+ |
static int |
91 |
|
ambsample( /* initial ambient division sample */ |
92 |
|
AMBHEMI *hp, |
93 |
|
int i, |
115 |
|
hlist[1] = j; |
116 |
|
hlist[2] = i; |
117 |
|
multisamp(spt, 2, urand(ilhash(hlist,3)+n)); |
118 |
< |
/* avoid coincident samples */ |
82 |
< |
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 |
< |
} |
118 |
> |
resample: |
119 |
|
SDsquare2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns); |
120 |
|
zd = sqrt(1. - spt[0]*spt[0] - spt[1]*spt[1]); |
121 |
|
for (ii = 3; ii--; ) |
123 |
|
spt[1]*hp->uy[ii] + |
124 |
|
zd*hp->rp->ron[ii]; |
125 |
|
checknorm(ar.rdir); |
126 |
+ |
/* avoid coincident samples */ |
127 |
+ |
if (!n && ambcollision(hp, i, j, ar.rdir)) { |
128 |
+ |
spt[0] = frandom(); spt[1] = frandom(); |
129 |
+ |
goto resample; |
130 |
+ |
} |
131 |
|
dimlist[ndims++] = AI(hp,i,j) + 90171; |
132 |
|
rayvalue(&ar); /* evaluate ray */ |
133 |
|
ndims--; |
215 |
|
float *earr = getambdiffs(hp); |
216 |
|
double e2rem = 0; |
217 |
|
AMBSAMP *ap; |
183 |
– |
RAY ar; |
218 |
|
float *ep; |
219 |
|
int i, j, n, nss; |
220 |
|
|
253 |
|
wt > (d = 0.8*intens(rcol)*r->rweight/(ambdiv*minweight))) |
254 |
|
wt = d; /* avoid ray termination */ |
255 |
|
n = sqrt(ambdiv * wt) + 0.5; |
256 |
< |
i = 1 + 8*(ambacc > FTINY); /* minimum number of samples */ |
256 |
> |
i = 1 + 5*(ambacc > FTINY); /* minimum number of samples */ |
257 |
|
if (n < i) |
258 |
|
n = i; |
259 |
|
/* allocate sampling array */ |
270 |
|
d = 1.0/(n*n); |
271 |
|
scalecolor(hp->acoef, d); |
272 |
|
/* make tangent plane axes */ |
273 |
< |
hp->uy[0] = 0.5 - frandom(); |
240 |
< |
hp->uy[1] = 0.5 - frandom(); |
241 |
< |
hp->uy[2] = 0.5 - frandom(); |
242 |
< |
for (i = 3; i--; ) |
243 |
< |
if ((-0.6 < r->ron[i]) & (r->ron[i] < 0.6)) |
244 |
< |
break; |
245 |
< |
if (i < 0) |
273 |
> |
if (!getperpendicular(hp->ux, r->ron, 1)) |
274 |
|
error(CONSISTENCY, "bad ray direction in samp_hemi"); |
247 |
– |
hp->uy[i] = 1.0; |
248 |
– |
VCROSS(hp->ux, hp->uy, r->ron); |
249 |
– |
normalize(hp->ux); |
275 |
|
VCROSS(hp->uy, r->ron, hp->ux); |
276 |
|
/* sample divisions */ |
277 |
|
for (i = hp->ns; i--; ) |
635 |
|
ambcorral(AMBHEMI *hp, FVECT uv[2], const double r0, const double r1) |
636 |
|
{ |
637 |
|
const double max_d = 1.0/(minarad*ambacc + 0.001); |
638 |
< |
const double ang_res = 0.5*PI/(hp->ns-1); |
639 |
< |
const double ang_step = ang_res/((int)(16/PI*ang_res) + (1+FTINY)); |
638 |
> |
const double ang_res = 0.5*PI/hp->ns; |
639 |
> |
const double ang_step = ang_res/((int)(16/PI*ang_res) + 1.01); |
640 |
|
double avg_d = 0; |
641 |
|
uint32 flgs = 0; |
642 |
|
FVECT vec; |
644 |
|
double ang, a1; |
645 |
|
int i, j; |
646 |
|
/* don't bother for a few samples */ |
647 |
< |
if (hp->ns < 12) |
647 |
> |
if (hp->ns < 8) |
648 |
|
return(0); |
649 |
|
/* check distances overhead */ |
650 |
|
for (i = hp->ns*3/4; i-- > hp->ns>>2; ) |
667 |
|
if ((r0*r0*u*u + r1*r1*v*v) * ap->d*ap->d <= u*u + v*v) |
668 |
|
continue; /* occluder outside ellipse */ |
669 |
|
ang = atan2a(v, u); /* else set direction flags */ |
670 |
< |
for (a1 = ang-.5*ang_res; a1 <= ang+.5*ang_res; a1 += ang_step) |
670 |
> |
for (a1 = ang-ang_res; a1 <= ang+ang_res; a1 += ang_step) |
671 |
|
flgs |= 1L<<(int)(16/PI*(a1 + 2.*PI*(a1 < 0))); |
672 |
|
} |
673 |
|
/* add low-angle incident (< 20deg) */ |
720 |
|
return(0); |
721 |
|
|
722 |
|
if ((ra == NULL) & (pg == NULL) & (dg == NULL) || |
723 |
< |
(hp->sampOK < 0) | (hp->ns < 9)) { |
723 |
> |
(hp->sampOK < 0) | (hp->ns < 6)) { |
724 |
|
free(hp); /* Hessian not requested/possible */ |
725 |
|
return(-1); /* value-only return value */ |
726 |
|
} |
768 |
|
ra[0] = maxarad; |
769 |
|
} |
770 |
|
/* flag encroached directions */ |
771 |
< |
if ((wt >= 0.89*AVGREFL) & (crlp != NULL)) |
771 |
> |
if (crlp != NULL) |
772 |
|
*crlp = ambcorral(hp, uv, ra[0]*ambacc, ra[1]*ambacc); |
773 |
|
if (pg != NULL) { /* cap gradient if necessary */ |
774 |
|
d = pg[0]*pg[0]*ra[0]*ra[0] + pg[1]*pg[1]*ra[1]*ra[1]; |