80 |
|
register NORMDAT *np = nnp; |
81 |
|
double ldot; |
82 |
|
double lrdiff, ltdiff; |
83 |
< |
double dtmp, d2; |
83 |
> |
double dtmp, d2, d3, d4; |
84 |
|
FVECT vtmp; |
85 |
|
COLOR ctmp; |
86 |
|
|
115 |
|
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
116 |
|
/* |
117 |
|
* Compute specular reflection coefficient using |
118 |
< |
* gaussian distribution model. |
118 |
> |
* Gaussian distribution model. |
119 |
|
*/ |
120 |
|
/* roughness */ |
121 |
|
dtmp = np->alpha2; |
128 |
|
vtmp[2] = ldir[2] - np->rp->rdir[2]; |
129 |
|
d2 = DOT(vtmp, np->pnorm); |
130 |
|
d2 *= d2; |
131 |
< |
d2 = (DOT(vtmp,vtmp) - d2) / d2; |
132 |
< |
/* gaussian */ |
133 |
< |
dtmp = exp(-d2/dtmp)/(4.*PI * np->pdot * dtmp); |
131 |
> |
d3 = DOT(vtmp,vtmp); |
132 |
> |
d4 = (d3 - d2) / d2; |
133 |
> |
/* new W-G-M-D model */ |
134 |
> |
dtmp = exp(-d4/dtmp) * d3 / (PI * d2*d2 * dtmp); |
135 |
|
/* worth using? */ |
136 |
|
if (dtmp > FTINY) { |
137 |
|
copycolor(ctmp, np->scolor); |
138 |
< |
dtmp *= omega; |
138 |
> |
dtmp *= ldot * omega; |
139 |
|
scalecolor(ctmp, dtmp); |
140 |
|
addcolor(cval, ctmp); |
141 |
|
} |
156 |
|
*/ |
157 |
|
/* roughness + source */ |
158 |
|
dtmp = np->alpha2 + omega*(1.0/PI); |
159 |
< |
/* gaussian */ |
159 |
> |
/* Gaussian */ |
160 |
|
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp); |
161 |
|
/* worth using? */ |
162 |
|
if (dtmp > FTINY) { |
366 |
|
|
367 |
|
|
368 |
|
static void |
369 |
< |
gaussamp( /* sample gaussian specular */ |
369 |
> |
gaussamp( /* sample Gaussian specular */ |
370 |
|
RAY *r, |
371 |
|
register NORMDAT *np |
372 |
|
) |