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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this target list:
(a1, b1, c1, d1)
(a2, b2, c2, d2)
(a3, b3, c3, d3)
....
What I want to do is injecting one more value (arbitrary angle in my case) to each point before I cull many of them - so that each point brings its angle data along.
Any hep would be greatly appreciated. TIA
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on for curves, if you make an algorithm that dynamically defines the possition of the controlpoints for NURBS curves as a function of the parameteres in F(t, a1,...,b1,...,c1,...)= x(t, a1, a2...)+y(t, b1, b2...)+ z(t, c1, c2...) or F(x, a, b ,c...)?
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nt B2[i] so B1[i]<=0 means no new connections allowed for point i ,so point i is deleted from B1, B2 updated accordingly.
Initialization:
B1: max number of connections x number of points
B2: all the points
B3: nothing (well null or something, need to create the branch)
Algo:
Get first point in B2, get his allowed number of connections N in B1, find N closest points in B2, create lines in B3, update B2 accordingly. Erase points with max connections (including the first point)
Next
Stop when no points available
At end of loop, B3 stores the created lines.
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