站长说的很对,补充一下: .~db4d]
Normal Vector J( TkXNm
The Normal Vector is a vector in 3D space that is used to orient the projection qArM|\l1
plane for the irradiance map. The plane is defined to be perpendicular to the l9~e".
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Normal Vector, and the irradiance incident on the selected surface is projected h
f)?1z4
onto this plane. When the map is displayed, the normal vector is pointing toward CT@ jZtg0
you. yu {d! {6
Up Vector X #dmo/L8
The Up Vector is a vector in 3D space that is used to orient the projection plane M7\szv\Zc=
for the irradiance map. The plane is defined so that the Up Vector is parallel to the 234p9A@
vertical side of the plane. The irradiance incident on the selected surface is tIi&;tw]
projected onto this plane. When the map is displayed, the up vector will point FZQP%]FX
toward the top of the screen.