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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, a1200)}) Is there any way I can make this list into {a1, a2, a3, a4, -a5, -a6, -a7, -a8, a9, a10, a11, a12, -a13, ..... , a1200} ? ( 4 positive signs then 4 negative signs and so on) - alternating every nth in general.
or
2. Is there any way (workaround) to get negative angle value from 2 vectors? I know 'ANGLE (of 2 vectors)' component by itself doesn't work and I know why too. I have feeling that the reflex angle output might be useful but again, matter of list manipulation.
Any help would be greatly appreciated. Thanks in advance.
Hyo
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ole refresh part so that it will try one combination at a time. I dont have a full understanding of how to do this given that everything in GH is runtime.
Outputs: A,B,C,D
A0: Cat
B0: Cat
C0: Cat
D0: Cat
A1: Cat
A2: Cat
A3: Cat
A4: Dog
etc, per refresh.....…