0.533000void brightfunc skyfunc2 skybright perezlum.cal010 1.382e+00 3.201e-01 1.066879 -0.754821 0.015485 -0.048998 -0.089403 0.066341 -0.860010 0.505947
The values in bold are then evaluated using the equations in the file perezlum.cal inside the RAYPATH directory in Radiance..
{ All-weather Angular Sky Luminance Distribution . Additional arguments required for calculation of skybright: A1 - diffus normalization A2 - ground brightness A3,A4,A5,A6,A7 - coefficients for the Perez model A8,A9,A10 - sun direction}skybright = wmean((Dz+1.01)^10, intersky, (Dz+1.01)^-10, A2 );wmean(a, x, b, y) = (a*x+b*y)/(a+b);intersky = if( (Dz-0.01), A1 * (1 + A3*Exp(A4/Dz) ) * ( 1 + A5*Exp(A6*gamma) + A7*cos(gamma)*cos(gamma) ), A1 * (1 + A3*Exp(A4/0.01) ) * ( 1 + A5*Exp(A6*gamma) + A7*cos(gamma)*cos(gamma) ) );
This data is then mapped to the "glow" material that represents the celestial hemisphere...You can edit the climate based sky produced by Honeybee and enter your own values. The other option would be to just use gendaylit from DOS Prompt.…
for waves, that is done with a 'phase shift', add 2*pi/4 radians (for a 90 deg shift) to your sin curve, could also be done using cos instead of sin for an inherent 90 deg shift
Added by mark zirinsky at 7:37pm on November 9, 2016
exact formula is inside /lib/skybright.cal if this can help you to find the name.
{ RCSid: $Id$ } { Sky brightness function for sunny and cloudy skies.
Additional arguments required for calculation of skybright:
A1 - 1 for CIE clear, 2 for CIE overcast, 3 for uniform, 4 for CIE intermediate A2 - zenith brightness A3 - ground plane brightness A4 - normalization factor based on sun direction A5,A6,A7 - sun direction }
cosgamma = Dx*A5 + Dy*A6 + Dz*A7;
gamma = Acos(cosgamma); { angle from sun to this point in sky }
zt = Acos(A7); { angle from zenith to sun }
eta = Acos(Dz); { angle from zenith to this point in sky }
wmean(a, x, b, y) : (a*x + b*y) / (a + b);
skybr = wmean((Dz+1.01)^10, select(A1, sunnysky, cloudysky, unifsky, intersky), (Dz+1.01)^-10, A3);
sunnysky = A2 * (.91 + 10*exp(-3*gamma) + .45*cosgamma*cosgamma) * if( Dz - .01, 1.0 - exp(-.32/Dz), 1.0) / A4;
cloudysky = A2 * (1 + 2*Dz)/3;
unifsky = A2;
intersky = A2 * ( (1.35*sin(5.631-3.59*eta)+3.12)*sin(4.396-2.6*zt) + 6.37 - eta ) / 2.326 * exp(gamma*-.563*((2.629-eta)*(1.562-zt)+.812)) / A4;
…
behave like this:{a1;b2;c3;d1;e2;f3;g1;h2}
The ping pong matching would behave like this:
{a1;b2;c3;d2;e1;f2;g3;h2}
with a boolean option it could repeat the first and last like this:
{a1;b2;c3;d3;e2;f1;g1;h2}
If this already exist please let me know
Thanks
bye…
Added by Frane Zilic at 10:15pm on August 19, 2012