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greg |
1.2 |
{ RCSid $Id: LaFortune1.cal,v 1.1 2014/03/18 16:16:37 greg Exp $ } |
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greg |
1.1 |
{ LaFortune reflectance model with one lobe } |
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{ Sample parameters (change these) } |
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rho_d : 0.136465483630983; |
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rho_s : 0.144594472775860; |
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Cx : -0.605122636448704; |
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Cy : -0.664960041454502; |
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Cz : 0.586571000768196; |
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n : 29.629194300125050; |
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{ Useful functions } |
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abs(x) : if(x, x, -x); |
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noneg(x) : if(x, x, 0); |
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{ Normalization factor based on parameters } |
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greg |
1.2 |
snf : (n+2)/(2*PI*max(abs(Cx),abs(Cy),abs(Cz))^n); |
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greg |
1.1 |
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{ Note that we assume i and o vectors are normalized, both pointing away } |
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lafortune(ix,iy,iz,ox,oy,oz) : if( -iz*oz, 0, |
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rho_d/PI + rho_s*snf*noneg(Cx*ix*ox + Cy*iy*oy + Cz*iz*oz)^n ); |
