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fr Φs1(xrj)
xrj
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1(x j)
w s2
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receiver
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Ψ1(xs)
B(xs)
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S2(p,ωin)
p
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p
ωin
s
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% " - &
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basis irradiance calculation
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basis irradiances
+
weights of O1
weight calculation
linear combination calculation
weights of O2
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indirect
illumination
calculation
O2
basis irradiances
O2
(a)
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