站长说的很对,补充一下: )!a$#"'
Normal Vector ~6sE an3p
The Normal Vector is a vector in 3D space that is used to orient the projection 9P0yv3
plane for the irradiance map. The plane is defined to be perpendicular to the !0Nf9
Normal Vector, and the irradiance incident on the selected surface is projected ~p^7X2% !
onto this plane. When the map is displayed, the normal vector is pointing toward HlRAD|]\
you. ;
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Up Vector : I)G v
The Up Vector is a vector in 3D space that is used to orient the projection plane ZqP7@fO_%
for the irradiance map. The plane is defined so that the Up Vector is parallel to the <m1sSghg
vertical side of the plane. The irradiance incident on the selected surface is w+Vk3c5uI)
projected onto this plane. When the map is displayed, the up vector will point Rf:<-C0T
toward the top of the screen.