站长说的很对,补充一下: kXMp()N8`
Normal Vector }rTH<!j
The Normal Vector is a vector in 3D space that is used to orient the projection e3?=1ZB
plane for the irradiance map. The plane is defined to be perpendicular to the 6[> lzEZ
Normal Vector, and the irradiance incident on the selected surface is projected uepyH
onto this plane. When the map is displayed, the normal vector is pointing toward ff"wg\O4
you. A =Wg0eYy\
Up Vector g`7XE
The Up Vector is a vector in 3D space that is used to orient the projection plane RLB3 -=9t
for the irradiance map. The plane is defined so that the Up Vector is parallel to the )+E[M!34
vertical side of the plane. The irradiance incident on the selected surface is BM%wZ:
s
projected onto this plane. When the map is displayed, the up vector will point nM
)C^$3<t
toward the top of the screen.