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 |
|
* Declarations of external symbols in ambient.h |
12 |
|
*/ |
13 |
|
|
23 |
|
|
24 |
|
typedef struct { |
25 |
|
RAY *rp; /* originating ray sample */ |
26 |
< |
FVECT ux, uy; /* tangent axis directions */ |
26 |
> |
FVECT ux, uy; /* tangent axis unit vectors */ |
27 |
|
int ns; /* number of samples per axis */ |
28 |
|
COLOR acoef; /* division contribution coefficient */ |
29 |
|
struct s_ambsamp { |
30 |
|
COLOR v; /* hemisphere sample value */ |
31 |
< |
float p[3]; /* intersection point */ |
31 |
> |
FVECT p; /* intersection point */ |
32 |
|
} sa[1]; /* sample array (extends struct) */ |
33 |
|
} AMBHEMI; /* ambient sample hemisphere */ |
34 |
|
|
35 |
|
#define ambsamp(h,i,j) (h)->sa[(i)*(h)->ns + (j)] |
36 |
|
|
37 |
+ |
typedef struct { |
38 |
+ |
FVECT r_i, r_i1, e_i, rcp, rI2_eJ2; |
39 |
+ |
double I1, I2; |
40 |
+ |
} FFTRI; /* vectors and coefficients for Hessian calculation */ |
41 |
|
|
42 |
+ |
|
43 |
|
static AMBHEMI * |
44 |
|
inithemi( /* initialize sampling hemisphere */ |
45 |
|
COLOR ac, |
55 |
|
wt > (d = 0.8*intens(ac)*r->rweight/(ambdiv*minweight))) |
56 |
|
wt = d; /* avoid ray termination */ |
57 |
|
n = sqrt(ambdiv * wt) + 0.5; |
58 |
< |
i = 1 + 4*(ambacc > FTINY); /* minimum number of samples */ |
58 |
> |
i = 1 + 5*(ambacc > FTINY); /* minimum number of samples */ |
59 |
|
if (n < i) |
60 |
|
n = i; |
61 |
|
/* allocate sampling array */ |
69 |
|
copycolor(hp->acoef, ac); |
70 |
|
d = 1.0/(n*n); |
71 |
|
scalecolor(hp->acoef, d); |
72 |
< |
/* make tangent axes */ |
73 |
< |
hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0; |
74 |
< |
for (i = 0; i < 3; i++) |
75 |
< |
if (r->rn[i] < 0.6 && r->rn[i] > -0.6) |
76 |
< |
break; |
77 |
< |
if (i >= 3) |
72 |
> |
/* make tangent plane axes */ |
73 |
> |
hp->uy[0] = hp->uy[1] = hp->uy[2] = 0; |
74 |
> |
for (i = 3; i--; ) |
75 |
> |
if ((0.6 < r->ron[i]) & (r->ron[i] < 0.6)) |
76 |
> |
hp->uy[i] = 0.1+frandom(); |
77 |
> |
if (DOT(hp->uy,hp->uy) <= FTINY) |
78 |
|
error(CONSISTENCY, "bad ray direction in inithemi()"); |
79 |
< |
hp->uy[i] = 1.0; |
71 |
< |
VCROSS(hp->ux, hp->uy, r->rn); |
79 |
> |
VCROSS(hp->ux, hp->uy, r->ron); |
80 |
|
normalize(hp->ux); |
81 |
< |
VCROSS(hp->uy, r->rn, hp->ux); |
81 |
> |
VCROSS(hp->uy, r->ron, hp->ux); |
82 |
|
/* we're ready to sample */ |
83 |
|
return(hp); |
84 |
|
} |
85 |
|
|
86 |
|
|
87 |
< |
static int |
87 |
> |
static struct s_ambsamp * |
88 |
|
ambsample( /* sample an ambient direction */ |
89 |
|
AMBHEMI *hp, |
90 |
|
int i, |
91 |
< |
int j, |
91 |
> |
int j |
92 |
|
) |
93 |
|
{ |
94 |
|
struct s_ambsamp *ap = &ambsamp(hp,i,j); |
95 |
|
RAY ar; |
96 |
< |
int hlist[3]; |
89 |
< |
double spt[2], dz; |
96 |
> |
double spt[2], zd; |
97 |
|
int ii; |
98 |
|
/* ambient coefficient for weight */ |
99 |
|
if (ambacc > FTINY) |
100 |
|
setcolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL); |
101 |
|
else |
102 |
|
copycolor(ar.rcoef, hp->acoef); |
103 |
< |
if (rayorigin(&ar, AMBIENT, hp->rp, ar.rcoef) < 0) { |
104 |
< |
setcolor(ap->v, 0., 0., 0.); |
98 |
< |
ap->r = 0.; |
99 |
< |
return(0); /* no sample taken */ |
100 |
< |
} |
103 |
> |
if (rayorigin(&ar, AMBIENT, hp->rp, ar.rcoef) < 0) |
104 |
> |
goto badsample; |
105 |
|
if (ambacc > FTINY) { |
106 |
|
multcolor(ar.rcoef, hp->acoef); |
107 |
|
scalecolor(ar.rcoef, 1./AVGREFL); |
108 |
|
} |
109 |
|
/* generate hemispherical sample */ |
110 |
< |
SDsquare2disk(spt, (i+frandom())/hp->ns, (j+frandom())/hp->ns); |
110 |
> |
SDsquare2disk(spt, (i+.1+.8*frandom())/hp->ns, |
111 |
> |
(j+.1+.8*frandom())/hp->ns ); |
112 |
|
zd = sqrt(1. - spt[0]*spt[0] - spt[1]*spt[1]); |
113 |
|
for (ii = 3; ii--; ) |
114 |
|
ar.rdir[ii] = spt[0]*hp->ux[ii] + |
118 |
|
dimlist[ndims++] = i*hp->ns + j + 90171; |
119 |
|
rayvalue(&ar); /* evaluate ray */ |
120 |
|
ndims--; |
121 |
+ |
/* limit vertex distance */ |
122 |
+ |
if (ar.rt > 10.0*thescene.cusize) |
123 |
+ |
ar.rt = 10.0*thescene.cusize; |
124 |
+ |
else if (ar.rt <= FTINY) /* should never happen! */ |
125 |
+ |
goto badsample; |
126 |
+ |
VSUM(ap->p, ar.rorg, ar.rdir, ar.rt); |
127 |
|
multcolor(ar.rcol, ar.rcoef); /* apply coefficient */ |
128 |
|
copycolor(ap->v, ar.rcol); |
129 |
< |
if (ar.rt > 20.0*maxarad) /* limit vertex distance */ |
130 |
< |
ar.rt = 20.0*maxarad; |
131 |
< |
VSUM(ap->p, ar.rorg, ar.rdir, ar.rt); |
132 |
< |
return(1); |
129 |
> |
return(ap); |
130 |
> |
badsample: |
131 |
> |
setcolor(ap->v, 0., 0., 0.); |
132 |
> |
VCOPY(ap->p, hp->rp->rop); |
133 |
> |
return(NULL); |
134 |
|
} |
135 |
|
|
136 |
|
|
137 |
+ |
/* Compute vectors and coefficients for Hessian/gradient calcs */ |
138 |
|
static void |
139 |
+ |
comp_fftri(FFTRI *ftp, FVECT ap0, FVECT ap1, FVECT rop) |
140 |
+ |
{ |
141 |
+ |
double rdot_cp, dot_e, dot_er, rdot_r, rdot_r1, J2; |
142 |
+ |
int i; |
143 |
+ |
|
144 |
+ |
VSUB(ftp->r_i, ap0, rop); |
145 |
+ |
VSUB(ftp->r_i1, ap1, rop); |
146 |
+ |
VSUB(ftp->e_i, ap1, ap0); |
147 |
+ |
VCROSS(ftp->rcp, ftp->r_i, ftp->r_i1); |
148 |
+ |
rdot_cp = 1.0/DOT(ftp->rcp,ftp->rcp); |
149 |
+ |
dot_e = DOT(ftp->e_i,ftp->e_i); |
150 |
+ |
dot_er = DOT(ftp->e_i, ftp->r_i); |
151 |
+ |
rdot_r = 1.0/DOT(ftp->r_i,ftp->r_i); |
152 |
+ |
rdot_r1 = 1.0/DOT(ftp->r_i1,ftp->r_i1); |
153 |
+ |
ftp->I1 = acos( DOT(ftp->r_i, ftp->r_i1) * sqrt(rdot_r*rdot_r1) ) * |
154 |
+ |
sqrt( rdot_cp ); |
155 |
+ |
ftp->I2 = ( DOT(ftp->e_i, ftp->r_i1)*rdot_r1 - dot_er*rdot_r + |
156 |
+ |
dot_e*ftp->I1 )*0.5*rdot_cp; |
157 |
+ |
J2 = ( 0.5*(rdot_r - rdot_r1) - dot_er*ftp->I2 ) / dot_e; |
158 |
+ |
for (i = 3; i--; ) |
159 |
+ |
ftp->rI2_eJ2[i] = ftp->I2*ftp->r_i[i] + J2*ftp->e_i[i]; |
160 |
+ |
} |
161 |
+ |
|
162 |
+ |
|
163 |
+ |
/* Compose 3x3 matrix from two vectors */ |
164 |
+ |
static void |
165 |
+ |
compose_matrix(FVECT mat[3], FVECT va, FVECT vb) |
166 |
+ |
{ |
167 |
+ |
mat[0][0] = 2.0*va[0]*vb[0]; |
168 |
+ |
mat[1][1] = 2.0*va[1]*vb[1]; |
169 |
+ |
mat[2][2] = 2.0*va[2]*vb[2]; |
170 |
+ |
mat[0][1] = mat[1][0] = va[0]*vb[1] + va[1]*vb[0]; |
171 |
+ |
mat[0][2] = mat[2][0] = va[0]*vb[2] + va[2]*vb[0]; |
172 |
+ |
mat[1][2] = mat[2][1] = va[1]*vb[2] + va[2]*vb[1]; |
173 |
+ |
} |
174 |
+ |
|
175 |
+ |
|
176 |
+ |
/* Compute partial 3x3 Hessian matrix for edge */ |
177 |
+ |
static void |
178 |
+ |
comp_hessian(FVECT hess[3], FFTRI *ftp, FVECT nrm) |
179 |
+ |
{ |
180 |
+ |
FVECT ncp; |
181 |
+ |
FVECT m1[3], m2[3], m3[3], m4[3]; |
182 |
+ |
double d1, d2, d3, d4; |
183 |
+ |
double I3, J3, K3; |
184 |
+ |
int i, j; |
185 |
+ |
/* compute intermediate coefficients */ |
186 |
+ |
d1 = 1.0/DOT(ftp->r_i,ftp->r_i); |
187 |
+ |
d2 = 1.0/DOT(ftp->r_i1,ftp->r_i1); |
188 |
+ |
d3 = 1.0/DOT(ftp->e_i,ftp->e_i); |
189 |
+ |
d4 = DOT(ftp->e_i, ftp->r_i); |
190 |
+ |
I3 = ( DOT(ftp->e_i, ftp->r_i1)*d2*d2 - d4*d1*d1 + 3.0/d3*ftp->I2 ) |
191 |
+ |
/ ( 4.0*DOT(ftp->rcp,ftp->rcp) ); |
192 |
+ |
J3 = 0.25*d3*(d1*d1 - d2*d2) - d4*d3*I3; |
193 |
+ |
K3 = d3*(ftp->I2 - I3/d1 - 2.0*d4*J3); |
194 |
+ |
/* intermediate matrices */ |
195 |
+ |
VCROSS(ncp, nrm, ftp->e_i); |
196 |
+ |
compose_matrix(m1, ncp, ftp->rI2_eJ2); |
197 |
+ |
compose_matrix(m2, ftp->r_i, ftp->r_i); |
198 |
+ |
compose_matrix(m3, ftp->e_i, ftp->e_i); |
199 |
+ |
compose_matrix(m4, ftp->r_i, ftp->e_i); |
200 |
+ |
d1 = DOT(nrm, ftp->rcp); |
201 |
+ |
d2 = -d1*ftp->I2; |
202 |
+ |
d1 *= 2.0; |
203 |
+ |
for (i = 3; i--; ) /* final matrix sum */ |
204 |
+ |
for (j = 3; j--; ) { |
205 |
+ |
hess[i][j] = m1[i][j] + d1*( I3*m2[i][j] + K3*m3[i][j] + |
206 |
+ |
2.0*J3*m4[i][j] ); |
207 |
+ |
hess[i][j] += d2*(i==j); |
208 |
+ |
hess[i][j] *= 1.0/PI; |
209 |
+ |
} |
210 |
+ |
} |
211 |
+ |
|
212 |
+ |
|
213 |
+ |
/* Reverse hessian calculation result for edge in other direction */ |
214 |
+ |
static void |
215 |
+ |
rev_hessian(FVECT hess[3]) |
216 |
+ |
{ |
217 |
+ |
int i; |
218 |
+ |
|
219 |
+ |
for (i = 3; i--; ) { |
220 |
+ |
hess[i][0] = -hess[i][0]; |
221 |
+ |
hess[i][1] = -hess[i][1]; |
222 |
+ |
hess[i][2] = -hess[i][2]; |
223 |
+ |
} |
224 |
+ |
} |
225 |
+ |
|
226 |
+ |
|
227 |
+ |
/* Add to radiometric Hessian from the given triangle */ |
228 |
+ |
static void |
229 |
+ |
add2hessian(FVECT hess[3], FVECT ehess1[3], |
230 |
+ |
FVECT ehess2[3], FVECT ehess3[3], COLORV v) |
231 |
+ |
{ |
232 |
+ |
int i, j; |
233 |
+ |
|
234 |
+ |
for (i = 3; i--; ) |
235 |
+ |
for (j = 3; j--; ) |
236 |
+ |
hess[i][j] += v*( ehess1[i][j] + ehess2[i][j] + ehess3[i][j] ); |
237 |
+ |
} |
238 |
+ |
|
239 |
+ |
|
240 |
+ |
/* Compute partial displacement form factor gradient for edge */ |
241 |
+ |
static void |
242 |
+ |
comp_gradient(FVECT grad, FFTRI *ftp, FVECT nrm) |
243 |
+ |
{ |
244 |
+ |
FVECT ncp; |
245 |
+ |
double f1; |
246 |
+ |
int i; |
247 |
+ |
|
248 |
+ |
f1 = 2.0*DOT(nrm, ftp->rcp); |
249 |
+ |
VCROSS(ncp, nrm, ftp->e_i); |
250 |
+ |
for (i = 3; i--; ) |
251 |
+ |
grad[i] = (-0.5/PI)*( ftp->I1*ncp[i] + f1*ftp->rI2_eJ2[i] ); |
252 |
+ |
} |
253 |
+ |
|
254 |
+ |
|
255 |
+ |
/* Reverse gradient calculation result for edge in other direction */ |
256 |
+ |
static void |
257 |
+ |
rev_gradient(FVECT grad) |
258 |
+ |
{ |
259 |
+ |
grad[0] = -grad[0]; |
260 |
+ |
grad[1] = -grad[1]; |
261 |
+ |
grad[2] = -grad[2]; |
262 |
+ |
} |
263 |
+ |
|
264 |
+ |
|
265 |
+ |
/* Add to displacement gradient from the given triangle */ |
266 |
+ |
static void |
267 |
+ |
add2gradient(FVECT grad, FVECT egrad1, FVECT egrad2, FVECT egrad3, COLORV v) |
268 |
+ |
{ |
269 |
+ |
int i; |
270 |
+ |
|
271 |
+ |
for (i = 3; i--; ) |
272 |
+ |
grad[i] += v*( egrad1[i] + egrad2[i] + egrad3[i] ); |
273 |
+ |
} |
274 |
+ |
|
275 |
+ |
|
276 |
+ |
/* Return brightness of furthest ambient sample */ |
277 |
+ |
static COLORV |
278 |
+ |
back_ambval(struct s_ambsamp *ap1, struct s_ambsamp *ap2, |
279 |
+ |
struct s_ambsamp *ap3, FVECT orig) |
280 |
+ |
{ |
281 |
+ |
COLORV vback; |
282 |
+ |
FVECT vec; |
283 |
+ |
double d2, d2best; |
284 |
+ |
|
285 |
+ |
VSUB(vec, ap1->p, orig); |
286 |
+ |
d2best = DOT(vec,vec); |
287 |
+ |
vback = colval(ap1->v,CIEY); |
288 |
+ |
VSUB(vec, ap2->p, orig); |
289 |
+ |
d2 = DOT(vec,vec); |
290 |
+ |
if (d2 > d2best) { |
291 |
+ |
d2best = d2; |
292 |
+ |
vback = colval(ap2->v,CIEY); |
293 |
+ |
} |
294 |
+ |
VSUB(vec, ap3->p, orig); |
295 |
+ |
d2 = DOT(vec,vec); |
296 |
+ |
if (d2 > d2best) |
297 |
+ |
return(colval(ap3->v,CIEY)); |
298 |
+ |
return(vback); |
299 |
+ |
} |
300 |
+ |
|
301 |
+ |
|
302 |
+ |
/* Compute anisotropic radii and eigenvector directions */ |
303 |
+ |
static int |
304 |
+ |
eigenvectors(FVECT uv[2], float ra[2], FVECT hessian[3]) |
305 |
+ |
{ |
306 |
+ |
double hess2[2][2]; |
307 |
+ |
FVECT a, b; |
308 |
+ |
double evalue[2], slope1, xmag1; |
309 |
+ |
int i; |
310 |
+ |
/* project Hessian to sample plane */ |
311 |
+ |
for (i = 3; i--; ) { |
312 |
+ |
a[i] = DOT(hessian[i], uv[0]); |
313 |
+ |
b[i] = DOT(hessian[i], uv[1]); |
314 |
+ |
} |
315 |
+ |
hess2[0][0] = DOT(uv[0], a); |
316 |
+ |
hess2[0][1] = DOT(uv[0], b); |
317 |
+ |
hess2[1][0] = DOT(uv[1], a); |
318 |
+ |
hess2[1][1] = DOT(uv[1], b); |
319 |
+ |
/* compute eigenvalues */ |
320 |
+ |
if ( quadratic(evalue, 1.0, -hess2[0][0]-hess2[1][1], |
321 |
+ |
hess2[0][0]*hess2[1][1]-hess2[0][1]*hess2[1][0]) != 2 || |
322 |
+ |
((evalue[0] = fabs(evalue[0])) <= FTINY*FTINY) | |
323 |
+ |
((evalue[1] = fabs(evalue[1])) <= FTINY*FTINY) ) |
324 |
+ |
error(INTERNAL, "bad eigenvalue calculation"); |
325 |
+ |
|
326 |
+ |
if (evalue[0] > evalue[1]) { |
327 |
+ |
ra[0] = sqrt(sqrt(4.0/evalue[0])); |
328 |
+ |
ra[1] = sqrt(sqrt(4.0/evalue[1])); |
329 |
+ |
slope1 = evalue[1]; |
330 |
+ |
} else { |
331 |
+ |
ra[0] = sqrt(sqrt(4.0/evalue[1])); |
332 |
+ |
ra[1] = sqrt(sqrt(4.0/evalue[0])); |
333 |
+ |
slope1 = evalue[0]; |
334 |
+ |
} |
335 |
+ |
/* compute unit eigenvectors */ |
336 |
+ |
if (fabs(hess2[0][1]) <= FTINY) |
337 |
+ |
return; /* uv OK as is */ |
338 |
+ |
slope1 = (slope1 - hess2[0][0]) / hess2[0][1]; |
339 |
+ |
xmag1 = sqrt(1.0/(1.0 + slope1*slope1)); |
340 |
+ |
for (i = 3; i--; ) { |
341 |
+ |
b[i] = xmag1*uv[0][i] + slope1*xmag1*uv[1][i]; |
342 |
+ |
a[i] = slope1*xmag1*uv[0][i] - xmag1*uv[1][i]; |
343 |
+ |
} |
344 |
+ |
VCOPY(uv[0], a); |
345 |
+ |
VCOPY(uv[1], b); |
346 |
+ |
} |
347 |
+ |
|
348 |
+ |
|
349 |
+ |
static void |
350 |
|
ambHessian( /* anisotropic radii & pos. gradient */ |
351 |
|
AMBHEMI *hp, |
352 |
|
FVECT uv[2], /* returned */ |
353 |
< |
float ra[2], /* returned */ |
354 |
< |
float pg[2] /* returned */ |
353 |
> |
float ra[2], /* returned (optional) */ |
354 |
> |
float pg[2] /* returned (optional) */ |
355 |
|
) |
356 |
|
{ |
357 |
< |
if (ra != NULL) { /* compute Hessian-derived radii */ |
358 |
< |
} else { /* else copy original tangent axes */ |
359 |
< |
VCOPY(uv[0], hp->ux); |
360 |
< |
VCOPY(uv[1], hp->uy); |
361 |
< |
} |
362 |
< |
if (pg == NULL) /* no position gradient requested? */ |
357 |
> |
static char memerrmsg[] = "out of memory in ambHessian()"; |
358 |
> |
FVECT (*hessrow)[3] = NULL; |
359 |
> |
FVECT *gradrow = NULL; |
360 |
> |
FVECT hessian[3]; |
361 |
> |
FVECT gradient; |
362 |
> |
FFTRI fftr; |
363 |
> |
int i, j; |
364 |
> |
/* be sure to assign unit vectors */ |
365 |
> |
VCOPY(uv[0], hp->ux); |
366 |
> |
VCOPY(uv[1], hp->uy); |
367 |
> |
/* clock-wise vertex traversal from sample POV */ |
368 |
> |
if (ra != NULL) { /* initialize Hessian row buffer */ |
369 |
> |
hessrow = (FVECT (*)[3])malloc(sizeof(FVECT)*3*(hp->ns-1)); |
370 |
> |
if (hessrow == NULL) |
371 |
> |
error(SYSTEM, memerrmsg); |
372 |
> |
memset(hessian, 0, sizeof(hessian)); |
373 |
> |
} else if (pg == NULL) /* bogus call? */ |
374 |
|
return; |
375 |
+ |
if (pg != NULL) { /* initialize form factor row buffer */ |
376 |
+ |
gradrow = (FVECT *)malloc(sizeof(FVECT)*(hp->ns-1)); |
377 |
+ |
if (gradrow == NULL) |
378 |
+ |
error(SYSTEM, memerrmsg); |
379 |
+ |
memset(gradient, 0, sizeof(gradient)); |
380 |
+ |
} |
381 |
+ |
/* compute first row of edges */ |
382 |
+ |
for (j = 0; j < hp->ns-1; j++) { |
383 |
+ |
comp_fftri(&fftr, ambsamp(hp,0,j).p, |
384 |
+ |
ambsamp(hp,0,j+1).p, hp->rp->rop); |
385 |
+ |
if (hessrow != NULL) |
386 |
+ |
comp_hessian(hessrow[j], &fftr, hp->rp->ron); |
387 |
+ |
if (gradrow != NULL) |
388 |
+ |
comp_gradient(gradrow[j], &fftr, hp->rp->ron); |
389 |
+ |
} |
390 |
+ |
/* sum each row of triangles */ |
391 |
+ |
for (i = 0; i < hp->ns-1; i++) { |
392 |
+ |
FVECT hesscol[3]; /* compute first vertical edge */ |
393 |
+ |
FVECT gradcol; |
394 |
+ |
comp_fftri(&fftr, ambsamp(hp,i,0).p, |
395 |
+ |
ambsamp(hp,i+1,0).p, hp->rp->rop); |
396 |
+ |
if (hessrow != NULL) |
397 |
+ |
comp_hessian(hesscol, &fftr, hp->rp->ron); |
398 |
+ |
if (gradrow != NULL) |
399 |
+ |
comp_gradient(gradcol, &fftr, hp->rp->ron); |
400 |
+ |
for (j = 0; j < hp->ns-1; j++) { |
401 |
+ |
FVECT hessdia[3]; /* compute triangle contributions */ |
402 |
+ |
FVECT graddia; |
403 |
+ |
COLORV backg; |
404 |
+ |
backg = back_ambval(&ambsamp(hp,i,j), &ambsamp(hp,i,j+1), |
405 |
+ |
&ambsamp(hp,i+1,j), hp->rp->rop); |
406 |
+ |
/* diagonal (inner) edge */ |
407 |
+ |
comp_fftri(&fftr, ambsamp(hp,i,j+1).p, |
408 |
+ |
ambsamp(hp,i+1,j).p, hp->rp->rop); |
409 |
+ |
if (hessrow != NULL) { |
410 |
+ |
comp_hessian(hessdia, &fftr, hp->rp->ron); |
411 |
+ |
rev_hessian(hesscol); |
412 |
+ |
add2hessian(hessian, hessrow[j], hessdia, hesscol, backg); |
413 |
+ |
} |
414 |
+ |
if (gradient != NULL) { |
415 |
+ |
comp_gradient(graddia, &fftr, hp->rp->ron); |
416 |
+ |
rev_gradient(gradcol); |
417 |
+ |
add2gradient(gradient, gradrow[j], graddia, gradcol, backg); |
418 |
+ |
} |
419 |
+ |
/* initialize edge in next row */ |
420 |
+ |
comp_fftri(&fftr, ambsamp(hp,i+1,j+1).p, |
421 |
+ |
ambsamp(hp,i+1,j).p, hp->rp->rop); |
422 |
+ |
if (hessrow != NULL) |
423 |
+ |
comp_hessian(hessrow[j], &fftr, hp->rp->ron); |
424 |
+ |
if (gradrow != NULL) |
425 |
+ |
comp_gradient(gradrow[j], &fftr, hp->rp->ron); |
426 |
+ |
/* new column edge & paired triangle */ |
427 |
+ |
backg = back_ambval(&ambsamp(hp,i,j+1), &ambsamp(hp,i+1,j+1), |
428 |
+ |
&ambsamp(hp,i+1,j), hp->rp->rop); |
429 |
+ |
comp_fftri(&fftr, ambsamp(hp,i,j+1).p, ambsamp(hp,i+1,j+1).p, |
430 |
+ |
hp->rp->rop); |
431 |
+ |
if (hessrow != NULL) { |
432 |
+ |
comp_hessian(hesscol, &fftr, hp->rp->ron); |
433 |
+ |
rev_hessian(hessdia); |
434 |
+ |
add2hessian(hessian, hessrow[j], hessdia, hesscol, backg); |
435 |
+ |
if (i < hp->ns-2) |
436 |
+ |
rev_hessian(hessrow[j]); |
437 |
+ |
} |
438 |
+ |
if (gradrow != NULL) { |
439 |
+ |
comp_gradient(gradcol, &fftr, hp->rp->ron); |
440 |
+ |
rev_gradient(graddia); |
441 |
+ |
add2gradient(gradient, gradrow[j], graddia, gradcol, backg); |
442 |
+ |
if (i < hp->ns-2) |
443 |
+ |
rev_gradient(gradrow[j]); |
444 |
+ |
} |
445 |
+ |
} |
446 |
+ |
} |
447 |
+ |
/* release row buffers */ |
448 |
+ |
if (hessrow != NULL) free(hessrow); |
449 |
+ |
if (gradrow != NULL) free(gradrow); |
450 |
+ |
|
451 |
+ |
if (ra != NULL) /* extract eigenvectors & radii */ |
452 |
+ |
eigenvectors(uv, ra, hessian); |
453 |
+ |
if (pg != NULL) { /* tangential position gradient */ |
454 |
+ |
pg[0] = DOT(gradient, uv[0]); |
455 |
+ |
pg[1] = DOT(gradient, uv[1]); |
456 |
+ |
} |
457 |
|
} |
458 |
|
|
459 |
+ |
|
460 |
+ |
/* Compute direction gradient from a hemispherical sampling */ |
461 |
+ |
static void |
462 |
+ |
ambdirgrad(AMBHEMI *hp, FVECT uv[2], float dg[2]) |
463 |
+ |
{ |
464 |
+ |
struct s_ambsamp *ap; |
465 |
+ |
double dgsum[2]; |
466 |
+ |
int n; |
467 |
+ |
FVECT vd; |
468 |
+ |
double gfact; |
469 |
+ |
|
470 |
+ |
dgsum[0] = dgsum[1] = 0.0; /* sum values times -tan(theta) */ |
471 |
+ |
for (ap = hp->sa, n = hp->ns*hp->ns; n--; ap++) { |
472 |
+ |
/* use vector for azimuth + 90deg */ |
473 |
+ |
VSUB(vd, ap->p, hp->rp->rop); |
474 |
+ |
/* brightness over cosine factor */ |
475 |
+ |
gfact = colval(ap->v,CIEY) / DOT(hp->rp->ron, vd); |
476 |
+ |
/* -sine = -proj_radius/vd_length */ |
477 |
+ |
dgsum[0] += DOT(uv[1], vd) * gfact; |
478 |
+ |
dgsum[1] -= DOT(uv[0], vd) * gfact; |
479 |
+ |
} |
480 |
+ |
dg[0] = dgsum[0] / (hp->ns*hp->ns); |
481 |
+ |
dg[1] = dgsum[1] / (hp->ns*hp->ns); |
482 |
+ |
} |
483 |
+ |
|
484 |
+ |
|
485 |
|
int |
486 |
|
doambient( /* compute ambient component */ |
487 |
|
COLOR rcol, /* input/output color */ |
488 |
|
RAY *r, |
489 |
|
double wt, |
490 |
< |
FVECT uv[2], /* returned */ |
491 |
< |
float ra[2], /* returned */ |
492 |
< |
float pg[2], /* returned */ |
493 |
< |
float dg[2] /* returned */ |
490 |
> |
FVECT uv[2], /* returned (optional) */ |
491 |
> |
float ra[2], /* returned (optional) */ |
492 |
> |
float pg[2], /* returned (optional) */ |
493 |
> |
float dg[2] /* returned (optional) */ |
494 |
|
) |
495 |
|
{ |
496 |
+ |
AMBHEMI *hp = inithemi(rcol, r, wt); |
497 |
|
int cnt = 0; |
498 |
|
FVECT my_uv[2]; |
155 |
– |
AMBHEMI *hp; |
499 |
|
double d, acol[3]; |
500 |
|
struct s_ambsamp *ap; |
501 |
|
int i, j; |
502 |
< |
/* initialize */ |
503 |
< |
if ((hp = inithemi(rcol, r, wt)) == NULL) |
502 |
> |
/* check/initialize */ |
503 |
> |
if (hp == NULL) |
504 |
|
return(0); |
505 |
|
if (uv != NULL) |
506 |
|
memset(uv, 0, sizeof(FVECT)*2); |
512 |
|
dg[0] = dg[1] = 0.0; |
513 |
|
/* sample the hemisphere */ |
514 |
|
acol[0] = acol[1] = acol[2] = 0.0; |
515 |
< |
for (i = hemi.ns; i--; ) |
516 |
< |
for (j = hemi.ns; j--; ) |
517 |
< |
if (ambsample(hp, i, j)) { |
175 |
< |
ap = &ambsamp(hp,i,j); |
515 |
> |
for (i = hp->ns; i--; ) |
516 |
> |
for (j = hp->ns; j--; ) |
517 |
> |
if ((ap = ambsample(hp, i, j)) != NULL) { |
518 |
|
addcolor(acol, ap->v); |
519 |
|
++cnt; |
520 |
|
} |
523 |
|
free(hp); |
524 |
|
return(0); /* no valid samples */ |
525 |
|
} |
526 |
< |
d = 1.0 / cnt; /* final indirect irradiance/PI */ |
185 |
< |
acol[0] *= d; acol[1] *= d; acol[2] *= d; |
186 |
< |
copycolor(rcol, acol); |
526 |
> |
copycolor(rcol, acol); /* final indirect irradiance/PI */ |
527 |
|
if (cnt < hp->ns*hp->ns || /* incomplete sampling? */ |
528 |
|
(ra == NULL) & (pg == NULL) & (dg == NULL)) { |
529 |
|
free(hp); |
530 |
|
return(-1); /* no radius or gradient calc. */ |
531 |
|
} |
532 |
< |
d = 0.01 * bright(rcol); /* add in 1% before Hessian comp. */ |
533 |
< |
if (d < FTINY) d = FTINY; |
534 |
< |
ap = hp->sa; /* using Y channel from here on... */ |
532 |
> |
if (bright(acol) > FTINY) /* normalize Y values */ |
533 |
> |
d = cnt/bright(acol); |
534 |
> |
else |
535 |
> |
d = 0.0; |
536 |
> |
ap = hp->sa; /* relative Y channel from here on... */ |
537 |
|
for (i = hp->ns*hp->ns; i--; ap++) |
538 |
< |
colval(ap->v,CIEY) = bright(ap->v) + d; |
538 |
> |
colval(ap->v,CIEY) = bright(ap->v)*d + 0.01; |
539 |
|
|
540 |
|
if (uv == NULL) /* make sure we have axis pointers */ |
541 |
|
uv = my_uv; |
542 |
|
/* compute radii & pos. gradient */ |
543 |
|
ambHessian(hp, uv, ra, pg); |
544 |
+ |
|
545 |
|
if (dg != NULL) /* compute direction gradient */ |
546 |
|
ambdirgrad(hp, uv, dg); |
547 |
< |
if (ra != NULL) { /* adjust/clamp radii */ |
548 |
< |
d = pow(wt, -0.25); |
549 |
< |
if ((ra[0] *= d) > maxarad) |
550 |
< |
ra[0] = maxarad; |
547 |
> |
|
548 |
> |
if (ra != NULL) { /* scale/clamp radii */ |
549 |
> |
if (pg != NULL) { |
550 |
> |
if (ra[0]*(d = fabs(pg[0])) > 1.0) |
551 |
> |
ra[0] = 1.0/d; |
552 |
> |
if (ra[1]*(d = fabs(pg[1])) > 1.0) |
553 |
> |
ra[1] = 1.0/d; |
554 |
> |
if (ra[0] > ra[1]) |
555 |
> |
ra[0] = ra[1]; |
556 |
> |
} |
557 |
> |
if (ra[0] < minarad) { |
558 |
> |
ra[0] = minarad; |
559 |
> |
if (ra[1] < minarad) |
560 |
> |
ra[1] = minarad; |
561 |
> |
} |
562 |
> |
ra[0] *= d = 1.0/sqrt(sqrt(wt)); |
563 |
|
if ((ra[1] *= d) > 2.0*ra[0]) |
564 |
|
ra[1] = 2.0*ra[0]; |
565 |
+ |
if (ra[1] > maxarad) { |
566 |
+ |
ra[1] = maxarad; |
567 |
+ |
if (ra[0] > maxarad) |
568 |
+ |
ra[0] = maxarad; |
569 |
+ |
} |
570 |
+ |
if (pg != NULL) { /* cap gradient if necessary */ |
571 |
+ |
d = pg[0]*pg[0]*ra[0]*ra[0] + pg[1]*pg[1]*ra[1]*ra[1]; |
572 |
+ |
if (d > 1.0) { |
573 |
+ |
d = 1.0/sqrt(d); |
574 |
+ |
pg[0] *= d; |
575 |
+ |
pg[1] *= d; |
576 |
+ |
} |
577 |
+ |
} |
578 |
|
} |
579 |
|
free(hp); /* clean up and return */ |
580 |
|
return(1); |