站长说的很对,补充一下: TJZar Nc$
Normal Vector RRl`;w?
The Normal Vector is a vector in 3D space that is used to orient the projection b.9[Vf_G
plane for the irradiance map. The plane is defined to be perpendicular to the #wkSru&LS
Normal Vector, and the irradiance incident on the selected surface is projected tC.etoh
onto this plane. When the map is displayed, the normal vector is pointing toward w U1[/
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Up Vector j'lC]}kH
The Up Vector is a vector in 3D space that is used to orient the projection plane {]dvzoE]
for the irradiance map. The plane is defined so that the Up Vector is parallel to the \c!e_rZ
vertical side of the plane. The irradiance incident on the selected surface is en6;I[\
projected onto this plane. When the map is displayed, the up vector will point C]h_co2eI
toward the top of the screen.