13 |
|
A5,A6,A7 - sun direction |
14 |
|
} |
15 |
|
|
16 |
+ |
cosgamma = Dx*A5 + Dy*A6 + Dz*A7; |
17 |
+ |
|
18 |
+ |
gamma = Acos(cosgamma); { angle from sun to this point in sky } |
19 |
+ |
|
20 |
+ |
zt = Acos(A7); { angle from zenith to sun } |
21 |
+ |
|
22 |
+ |
eta = Acos(Dz); { angle from zenith to this point in sky } |
23 |
+ |
|
24 |
+ |
wmean(a, x, b, y) : (a*x + b*y) / (a + b); |
25 |
+ |
|
26 |
|
skybr = wmean((Dz+1.01)^10, |
27 |
|
select(A1, sunnysky, cloudysky, unifsky, intersky), |
28 |
|
(Dz+1.01)^-10, A3); |
29 |
|
|
20 |
– |
wmean(a, x, b, y) = (a*x + b*y) / (a + b); |
21 |
– |
|
30 |
|
sunnysky = A2 * (.91 + 10*exp(-3*gamma) + .45*cosgamma*cosgamma) |
31 |
|
* if( Dz - .01, 1.0 - exp(-.32/Dz), 1.0) / A4; |
32 |
|
|
37 |
|
intersky = A2 * ( (1.35*sin(5.631-3.59*eta)+3.12)*sin(4.396-2.6*zt) |
38 |
|
+ 6.37 - eta ) / 2.326 * |
39 |
|
exp(gamma*-.563*((2.629-eta)*(1.562-zt)+.812)) / A4; |
32 |
– |
|
33 |
– |
cosgamma = Dx*A5 + Dy*A6 + Dz*A7; |
34 |
– |
|
35 |
– |
gamma = Acos(cosgamma); { angle from sun to this point in sky } |
36 |
– |
|
37 |
– |
zt = Acos(A7); { angle from zenith to sun } |
38 |
– |
|
39 |
– |
eta = Acos(Dz); { angle from zenith to this point in sky } |