站长说的很对,补充一下: nShXY6bA
Normal Vector ;py9,Wno
The Normal Vector is a vector in 3D space that is used to orient the projection >O<a9wz
plane for the irradiance map. The plane is defined to be perpendicular to the #Lpw8b6
Normal Vector, and the irradiance incident on the selected surface is projected Pc*lHoVL
onto this plane. When the map is displayed, the normal vector is pointing toward a7c`[
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Up Vector p@kRo#~l
The Up Vector is a vector in 3D space that is used to orient the projection plane y%ij)vQY
for the irradiance map. The plane is defined so that the Up Vector is parallel to the -N% V5 TN
vertical side of the plane. The irradiance incident on the selected surface is &BLCP d
projected onto this plane. When the map is displayed, the up vector will point SGSyO0O
toward the top of the screen.