20 |
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#define GRIDRES 200 /* max. grid resolution per side */ |
21 |
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#endif |
22 |
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|
23 |
< |
#define RSCA 1.9 /* radius scaling factor (empirical) */ |
24 |
< |
#define MSCA .12 /* magnitude scaling (empirical) */ |
23 |
> |
#define RSCA 3. /* radius scaling factor (empirical) */ |
24 |
> |
#define MSCA .2 /* magnitude scaling (empirical) */ |
25 |
|
|
26 |
+ |
#define R2ANG(c) (((c)+.5)*(M_PI/(1<<16))) |
27 |
+ |
#define ANG2R(r) (int)((r)*((1<<16)/M_PI)) |
28 |
+ |
|
29 |
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typedef struct { |
30 |
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float vsum; /* BSDF sum */ |
31 |
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unsigned short nval; /* number of values in sum */ |
32 |
< |
unsigned short hrad2; /* half radius squared */ |
32 |
> |
unsigned short crad; /* radius (coded angle) */ |
33 |
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} GRIDVAL; /* grid value */ |
34 |
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|
35 |
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typedef struct { |
36 |
< |
float bsdf; /* BSDF value at peak */ |
37 |
< |
unsigned short rad; /* radius */ |
36 |
> |
float bsdf; /* lobe value at peak */ |
37 |
> |
unsigned short crad; /* radius (coded angle) */ |
38 |
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unsigned char gx, gy; /* grid position */ |
39 |
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} RBFVAL; /* radial basis function value */ |
40 |
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|
80 |
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if (bsdf_grid[i][j].nval) { |
81 |
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newnode->rbfa[nn].bsdf = MSCA*bsdf_grid[i][j].vsum / |
82 |
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(double)bsdf_grid[i][j].nval; |
83 |
< |
newnode->rbfa[nn].rad = |
81 |
< |
(int)(2.*RSCA*sqrt((double)bsdf_grid[i][j].hrad2) + .5); |
83 |
> |
newnode->rbfa[nn].crad = RSCA*bsdf_grid[i][j].crad + .5; |
84 |
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newnode->rbfa[nn].gx = i; |
85 |
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newnode->rbfa[nn].gy = j; |
86 |
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++nn; |
118 |
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vec[2] = 1. - r2; |
119 |
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} |
120 |
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|
119 |
– |
/* Evaluate RBF at this grid position */ |
120 |
– |
static double |
121 |
– |
eval_rbfrep2(const RBFLIST *rp, int xi, int yi) |
122 |
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{ |
123 |
– |
double res = .0; |
124 |
– |
const RBFVAL *rbfp; |
125 |
– |
double sig2; |
126 |
– |
int x2, y2; |
127 |
– |
int n; |
128 |
– |
|
129 |
– |
rbfp = rp->rbfa; |
130 |
– |
for (n = rp->nrbf; n--; rbfp++) { |
131 |
– |
x2 = (signed)rbfp->gx - xi; |
132 |
– |
x2 *= x2; |
133 |
– |
y2 = (signed)rbfp->gy - yi; |
134 |
– |
y2 *= y2; |
135 |
– |
sig2 = -.5*(x2 + y2)/(double)(rbfp->rad*rbfp->rad); |
136 |
– |
if (sig2 > -19.) |
137 |
– |
res += rbfp->bsdf * exp(sig2); |
138 |
– |
} |
139 |
– |
return(res); |
140 |
– |
} |
141 |
– |
|
121 |
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/* Evaluate RBF for BSDF at the given normalized outgoing direction */ |
122 |
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static double |
123 |
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eval_rbfrep(const RBFLIST *rp, const FVECT outvec) |
131 |
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rbfp = rp->rbfa; |
132 |
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for (n = rp->nrbf; n--; rbfp++) { |
133 |
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vec_from_pos(odir, rbfp->gx, rbfp->gy); |
134 |
< |
sig2 = (DOT(odir, outvec) - 1.) / |
135 |
< |
((M_PI*M_PI/(double)(GRIDRES*GRIDRES)) * |
157 |
< |
rbfp->rad*rbfp->rad); |
134 |
> |
sig2 = R2ANG(rbfp->crad); |
135 |
> |
sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2); |
136 |
|
if (sig2 > -19.) |
137 |
|
res += rbfp->bsdf * exp(sig2); |
138 |
|
} |
219 |
|
static void |
220 |
|
compute_radii(void) |
221 |
|
{ |
222 |
< |
unsigned char fill_grid[GRIDRES][GRIDRES]; |
223 |
< |
int r, r2, lastr2; |
224 |
< |
int i, j, jn, ii, jj, inear, jnear; |
225 |
< |
/* proceed in zig-zag */ |
226 |
< |
lastr2 = GRIDRES*GRIDRES; |
222 |
> |
unsigned short fill_grid[GRIDRES][GRIDRES]; |
223 |
> |
FVECT ovec0, ovec1; |
224 |
> |
double ang2, lastang2; |
225 |
> |
int r2, lastr2; |
226 |
> |
int r, i, j, jn, ii, jj, inear, jnear; |
227 |
> |
|
228 |
> |
r = GRIDRES/2; /* proceed in zig-zag */ |
229 |
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for (i = 0; i < GRIDRES; i++) |
230 |
|
for (jn = 0; jn < GRIDRES; jn++) { |
231 |
|
j = (i&1) ? jn : GRIDRES-1-jn; |
232 |
|
if (bsdf_grid[i][j].nval) /* find empty grid pos. */ |
233 |
|
continue; |
234 |
< |
r = (int)sqrt((double)lastr2) + 2; |
234 |
> |
vec_from_pos(ovec0, i, j); |
235 |
|
inear = jnear = -1; /* find nearest non-empty */ |
236 |
< |
lastr2 = 2*GRIDRES*GRIDRES; |
236 |
> |
lastang2 = M_PI*M_PI; |
237 |
|
for (ii = i-r; ii <= i+r; ii++) { |
238 |
|
if (ii < 0) continue; |
239 |
|
if (ii >= GRIDRES) break; |
242 |
|
if (jj >= GRIDRES) break; |
243 |
|
if (!bsdf_grid[ii][jj].nval) |
244 |
|
continue; |
245 |
< |
r2 = (ii-i)*(ii-i) + (jj-j)*(jj-j); |
246 |
< |
if (r2 >= lastr2) |
245 |
> |
vec_from_pos(ovec1, ii, jj); |
246 |
> |
ang2 = 2. - 2.*DOT(ovec0,ovec1); |
247 |
> |
if (ang2 >= lastang2) |
248 |
|
continue; |
249 |
< |
lastr2 = r2; |
249 |
> |
lastang2 = ang2; |
250 |
|
inear = ii; jnear = jj; |
251 |
|
} |
252 |
|
} |
253 |
< |
/* record if > previous */ |
254 |
< |
if (bsdf_grid[inear][jnear].hrad2 < lastr2) |
255 |
< |
bsdf_grid[inear][jnear].hrad2 = lastr2; |
253 |
> |
if (inear < 0) { |
254 |
> |
fputs("Could not find non-empty neighbor!\n", stderr); |
255 |
> |
exit(1); |
256 |
> |
} |
257 |
> |
ang2 = sqrt(lastang2); |
258 |
> |
r = ANG2R(ang2); /* record if > previous */ |
259 |
> |
if (r > bsdf_grid[inear][jnear].crad) |
260 |
> |
bsdf_grid[inear][jnear].crad = r; |
261 |
> |
/* next search radius */ |
262 |
> |
r = ang2*(2.*GRIDRES/M_PI) + 1; |
263 |
|
} |
264 |
< |
/* fill in others */ |
264 |
> |
/* fill in neighbors */ |
265 |
|
memset(fill_grid, 0, sizeof(fill_grid)); |
266 |
|
for (i = 0; i < GRIDRES; i++) |
267 |
|
for (j = 0; j < GRIDRES; j++) { |
268 |
|
if (!bsdf_grid[i][j].nval) |
269 |
< |
continue; |
270 |
< |
if (bsdf_grid[i][j].hrad2) |
271 |
< |
continue; |
269 |
> |
continue; /* no value -- skip */ |
270 |
> |
if (bsdf_grid[i][j].crad) |
271 |
> |
continue; /* has distance already */ |
272 |
|
r = GRIDRES/20; |
273 |
< |
lastr2 = 2*r*r; |
273 |
> |
lastr2 = 2*r*r + 1; |
274 |
|
for (ii = i-r; ii <= i+r; ii++) { |
275 |
|
if (ii < 0) continue; |
276 |
|
if (ii >= GRIDRES) break; |
277 |
|
for (jj = j-r; jj <= j+r; jj++) { |
278 |
|
if (jj < 0) continue; |
279 |
|
if (jj >= GRIDRES) break; |
280 |
< |
if (!bsdf_grid[ii][jj].hrad2) |
280 |
> |
if (!bsdf_grid[ii][jj].crad) |
281 |
|
continue; |
282 |
+ |
/* OK to use approx. closest */ |
283 |
|
r2 = (ii-i)*(ii-i) + (jj-j)*(jj-j); |
284 |
|
if (r2 >= lastr2) |
285 |
|
continue; |
286 |
< |
fill_grid[i][j] = bsdf_grid[ii][jj].hrad2; |
286 |
> |
fill_grid[i][j] = bsdf_grid[ii][jj].crad; |
287 |
|
lastr2 = r2; |
288 |
|
} |
289 |
|
} |
290 |
|
} |
291 |
+ |
/* copy back filled entries */ |
292 |
|
for (i = 0; i < GRIDRES; i++) |
293 |
|
for (j = 0; j < GRIDRES; j++) |
294 |
|
if (fill_grid[i][j]) |
295 |
< |
bsdf_grid[i][j].hrad2 = fill_grid[i][j]; |
295 |
> |
bsdf_grid[i][j].crad = fill_grid[i][j]; |
296 |
|
} |
297 |
|
|
298 |
|
/* Cull points for more uniform distribution */ |
299 |
|
static void |
300 |
|
cull_values(void) |
301 |
|
{ |
302 |
< |
int i, j, ii, jj, r, r2; |
302 |
> |
FVECT ovec0, ovec1; |
303 |
> |
double maxang, maxang2; |
304 |
> |
int i, j, ii, jj, r; |
305 |
|
/* simple greedy algorithm */ |
306 |
|
for (i = 0; i < GRIDRES; i++) |
307 |
|
for (j = 0; j < GRIDRES; j++) { |
308 |
|
if (!bsdf_grid[i][j].nval) |
309 |
|
continue; |
310 |
< |
if (!bsdf_grid[i][j].hrad2) |
311 |
< |
continue; |
312 |
< |
r = (int)(2.*sqrt((double)bsdf_grid[i][j].hrad2) + .9999); |
310 |
> |
if (!bsdf_grid[i][j].crad) |
311 |
> |
continue; /* shouldn't happen */ |
312 |
> |
vec_from_pos(ovec0, i, j); |
313 |
> |
maxang = 2.*R2ANG(bsdf_grid[i][j].crad); |
314 |
> |
if (maxang > ovec0[2]) /* clamp near horizon */ |
315 |
> |
maxang = ovec0[2]; |
316 |
> |
r = maxang*(2.*GRIDRES/M_PI) + 1; |
317 |
> |
maxang2 = maxang*maxang; |
318 |
|
for (ii = i-r; ii <= i+r; ii++) { |
319 |
|
if (ii < 0) continue; |
320 |
|
if (ii >= GRIDRES) break; |
323 |
|
if (jj >= GRIDRES) break; |
324 |
|
if (!bsdf_grid[ii][jj].nval) |
325 |
|
continue; |
326 |
< |
r2 = (ii-i)*(ii-i) + (jj-j)*(jj-j); |
327 |
< |
if (!r2 | (r2 > r*r)) |
326 |
> |
if ((ii == i) & (jj == j)) |
327 |
> |
continue; /* don't get self-absorbed */ |
328 |
> |
vec_from_pos(ovec1, ii, jj); |
329 |
> |
if (2. - 2.*DOT(ovec0,ovec1) >= maxang2) |
330 |
|
continue; |
331 |
< |
/* absorb victim's value */ |
331 |
> |
/* absorb sum */ |
332 |
|
bsdf_grid[i][j].vsum += bsdf_grid[ii][jj].vsum; |
333 |
|
bsdf_grid[i][j].nval += bsdf_grid[ii][jj].nval; |
334 |
< |
memset(&bsdf_grid[ii][jj], 0, sizeof(GRIDVAL)); |
334 |
> |
/* keep value, though */ |
335 |
> |
bsdf_grid[ii][jj].vsum /= (double)bsdf_grid[ii][jj].nval; |
336 |
> |
bsdf_grid[ii][jj].nval = 0; |
337 |
|
} |
338 |
|
} |
339 |
|
} |