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{ RCSid $Id$ } |
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{ |
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Synthesize light probe using Spherical Harmonic coefficients |
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|
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2/16/2005 G. Ward |
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|
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Constants: |
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map - light probe mapping (1=angular, 2=mirror) |
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rcoef(i) - red coefficient array |
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gcoef(i) - green coefficient array |
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bcoef(i) - blue coefficient array |
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Usage: |
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pcomb -x 640 -y 640 -e 'map:1' -f spharm.cal -f genSH.cal \ |
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-f coef.cal > probe.pic |
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} |
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map : 1; { just angular for now } |
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|
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h = 1/xres*x - .5; |
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v = 1/yres*y - .5; |
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|
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beta_ang = 2*PI*sqrt(h*h + v*v); |
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gamma_ang = atan2(v, h); |
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sine_beta_ang = sin(beta_ang); |
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Dx_ang = cos(beta_ang); |
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Dy_ang = cos(gamma_ang)*sine_beta_ang; |
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Dz_ang = sin(gamma_ang)*sine_beta_ang; |
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theta_ang = acos(Dz_ang); |
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phi_ang = atan2(Dy_ang, Dx_ang); |
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|
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cond = select(map, PI-1e-4-beta_ang); |
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theta = select(map, theta_ang); |
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phi = select(map, phi_ang); |
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|
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ro = if(cond, SphericalHarmonicF(rcoef,theta_ang,phi_ang), 0); |
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go = if(cond, SphericalHarmonicF(gcoef,theta_ang,phi_ang), 0); |
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bo = if(cond, SphericalHarmonicF(bcoef,theta_ang,phi_ang), 0); |
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|
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{ Uncomment for luminance only } |
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{ |
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lo = if(cond, SphericalHarmonicF(lcoef,theta_ang,phi_ang), 0); |
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} |
