站长说的很对,补充一下: "\%On >
Normal Vector <U Zd;e@
The Normal Vector is a vector in 3D space that is used to orient the projection 1`0#HSO
plane for the irradiance map. The plane is defined to be perpendicular to the *~XA'Vw!
Normal Vector, and the irradiance incident on the selected surface is projected uzOYVN$t
onto this plane. When the map is displayed, the normal vector is pointing toward C@\{ehG
you. xb2?lL]
Up Vector >`RRP}u=u
The Up Vector is a vector in 3D space that is used to orient the projection plane PyC0Q\$%
for the irradiance map. The plane is defined so that the Up Vector is parallel to the Dr3n+Q
vertical side of the plane. The irradiance incident on the selected surface is OR6ML-|
projected onto this plane. When the map is displayed, the up vector will point 4<,|*hAT
toward the top of the screen.