A low-resolution work. Real time motion capture display made with an 11x8 (88) pixels iPad matrix using Grasshopper + Firefly + Pure Data + TouchOSC for iPad.
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.…
am doing the paneling tutorial from the first primer..pg 88. i baked it but while selecting the multiple geometries i cannot select individual ones, they are selected as surfaces..is that ok or .....?
Added by SHILPA PANDE at 6:25am on February 16, 2013
xtract A1, A2, B1, B2 as one set, A2, A3, B2, B3 as the second set, A3, A4, B3, B4...etc. as the third set and so on. How can I get about doing this?
Any help would be much appreciated!
Thanks,
Ben…
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;
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