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extern double specjitter; /* specular sampling jitter */ |
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/* |
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* This anisotropic reflection model uses a variant on the |
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* exponential Gaussian used in normal.c. |
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> |
* This routine implements the anisotropic Gaussian |
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* model described by Ward in Siggraph `92 article. |
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* We orient the surface towards the incoming ray, so a single |
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* surface can be used to represent an infinitely thin object. |
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* |
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dtmp2 *= dtmp2 / av2; |
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/* gaussian */ |
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dtmp = (dtmp1 + dtmp2) / (1.0 + DOT(np->pnorm, h)); |
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< |
dtmp = exp(-2.0*dtmp) * 1.0/(4.0*PI) |
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> |
dtmp = exp(-2.0*dtmp) * (1.0/4.0/PI) |
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* sqrt(ldot/(np->pdot*au2*av2)); |
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/* worth using? */ |
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if (dtmp > FTINY) { |
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h[0] = ldir[0] - np->prdir[0]; |
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h[1] = ldir[1] - np->prdir[1]; |
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h[2] = ldir[2] - np->prdir[2]; |
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< |
dtmp = DOT(h,np->pnorm); |
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< |
dtmp = DOT(h,h) - dtmp*dtmp; |
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> |
dtmp = DOT(h,h); |
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if (dtmp > FTINY*FTINY) { |
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< |
dtmp1 = DOT(h,np->u); |
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< |
dtmp1 = dtmp1*dtmp1 / (au2*dtmp); |
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< |
dtmp2 = DOT(h,np->v); |
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< |
dtmp2 = dtmp2*dtmp2 / (av2*dtmp); |
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< |
dtmp = 2. - 2.*DOT(ldir,np->prdir); |
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< |
dtmp *= dtmp1 + dtmp2; |
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> |
dtmp1 = DOT(h,np->pnorm); |
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> |
dtmp = 1.0 - dtmp1*dtmp1/dtmp; |
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> |
if (dtmp > FTINY*FTINY) { |
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> |
dtmp1 = DOT(h,np->u); |
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> |
dtmp1 = dtmp1*dtmp1 / au2; |
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> |
dtmp2 = DOT(h,np->v); |
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> |
dtmp2 = dtmp2*dtmp2 / av2; |
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dtmp = (dtmp1 + dtmp2) / dtmp; |
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} |
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} else |
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dtmp = 0.0; |
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/* gaussian */ |
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< |
dtmp = exp(-dtmp) * 1.0/(4.0*PI) |
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> |
dtmp = exp(-dtmp) * (1.0/PI) |
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* sqrt(-ldot/(np->pdot*au2*av2)); |
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/* worth using? */ |
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if (dtmp > FTINY) { |
