站长说的很对,补充一下: 2]$
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Normal Vector fG+/p 0sJ?
The Normal Vector is a vector in 3D space that is used to orient the projection ':}
plane for the irradiance map. The plane is defined to be perpendicular to the gCVgL]jj(
Normal Vector, and the irradiance incident on the selected surface is projected WB:NV=&^
onto this plane. When the map is displayed, the normal vector is pointing toward DRo?7_
you. cVx#dDdA
Up Vector LQ7.RK
The Up Vector is a vector in 3D space that is used to orient the projection plane 6@"lIKeP
for the irradiance map. The plane is defined so that the Up Vector is parallel to the th$?#4SbR
vertical side of the plane. The irradiance incident on the selected surface is l(o#N'!j4
projected onto this plane. When the map is displayed, the up vector will point sS 5aJ}Qs
toward the top of the screen.