| 320 |
|
FVECT h; |
| 321 |
|
double rv[2]; |
| 322 |
|
double d, sinp, cosp; |
| 323 |
< |
int confuse; |
| 323 |
> |
int ntries; |
| 324 |
|
register int i; |
| 325 |
|
/* compute reflection */ |
| 326 |
|
if (np->specfl & SP_REFL && |
| 327 |
|
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
| 328 |
– |
confuse = 0; |
| 328 |
|
dimlist[ndims++] = (int)np->mp; |
| 329 |
< |
refagain: |
| 330 |
< |
dimlist[ndims] = confuse += 3601; |
| 331 |
< |
d = urand(ilhash(dimlist,ndims+1)+samplendx); |
| 332 |
< |
multisamp(rv, 2, d); |
| 333 |
< |
d = 2.0*PI * rv[0]; |
| 334 |
< |
cosp = np->u_alpha * cos(d); |
| 335 |
< |
sinp = np->v_alpha * sin(d); |
| 336 |
< |
d = sqrt(cosp*cosp + sinp*sinp); |
| 337 |
< |
cosp /= d; |
| 338 |
< |
sinp /= d; |
| 339 |
< |
if (rv[1] <= FTINY) |
| 340 |
< |
d = 1.0; |
| 341 |
< |
else |
| 342 |
< |
d = sqrt( -log(rv[1]) / |
| 343 |
< |
(cosp*cosp/(np->u_alpha*np->u_alpha) + |
| 344 |
< |
sinp*sinp/(np->v_alpha*np->v_alpha)) ); |
| 345 |
< |
for (i = 0; i < 3; i++) |
| 346 |
< |
h[i] = np->pnorm[i] + |
| 329 |
> |
for (ntries = 0; ntries < 10; ntries++) { |
| 330 |
> |
dimlist[ndims] = ntries * 3601; |
| 331 |
> |
d = urand(ilhash(dimlist,ndims+1)+samplendx); |
| 332 |
> |
multisamp(rv, 2, d); |
| 333 |
> |
d = 2.0*PI * rv[0]; |
| 334 |
> |
cosp = np->u_alpha * cos(d); |
| 335 |
> |
sinp = np->v_alpha * sin(d); |
| 336 |
> |
d = sqrt(cosp*cosp + sinp*sinp); |
| 337 |
> |
cosp /= d; |
| 338 |
> |
sinp /= d; |
| 339 |
> |
if (rv[1] <= FTINY) |
| 340 |
> |
d = 1.0; |
| 341 |
> |
else |
| 342 |
> |
d = sqrt(-log(rv[1]) / |
| 343 |
> |
(cosp*cosp/(np->u_alpha*np->u_alpha) + |
| 344 |
> |
sinp*sinp/(np->v_alpha*np->v_alpha))); |
| 345 |
> |
for (i = 0; i < 3; i++) |
| 346 |
> |
h[i] = np->pnorm[i] + |
| 347 |
|
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 348 |
< |
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
| 349 |
< |
for (i = 0; i < 3; i++) |
| 350 |
< |
sr.rdir[i] = r->rdir[i] + d*h[i]; |
| 351 |
< |
if (DOT(sr.rdir, r->ron) <= FTINY) /* oops! */ |
| 352 |
< |
goto refagain; |
| 353 |
< |
rayvalue(&sr); |
| 354 |
< |
multcolor(sr.rcol, np->scolor); |
| 355 |
< |
addcolor(r->rcol, sr.rcol); |
| 348 |
> |
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
| 349 |
> |
for (i = 0; i < 3; i++) |
| 350 |
> |
sr.rdir[i] = r->rdir[i] + d*h[i]; |
| 351 |
> |
if (DOT(sr.rdir, r->ron) > FTINY) { |
| 352 |
> |
rayvalue(&sr); |
| 353 |
> |
multcolor(sr.rcol, np->scolor); |
| 354 |
> |
addcolor(r->rcol, sr.rcol); |
| 355 |
> |
break; |
| 356 |
> |
} |
| 357 |
> |
} |
| 358 |
|
ndims--; |
| 359 |
|
} |
| 360 |
|
/* compute transmission */ |
