站长说的很对,补充一下: o HMo>*?
Normal Vector k4,BNJt'Z
The Normal Vector is a vector in 3D space that is used to orient the projection 0ge$ p,
plane for the irradiance map. The plane is defined to be perpendicular to the z>jUR,!GT
Normal Vector, and the irradiance incident on the selected surface is projected W ZazJ=27}
onto this plane. When the map is displayed, the normal vector is pointing toward i O/K nH
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Up Vector +zrAG24q
The Up Vector is a vector in 3D space that is used to orient the projection plane XQ%?
for the irradiance map. The plane is defined so that the Up Vector is parallel to the n8uv#DsdK
vertical side of the plane. The irradiance incident on the selected surface is SF}<{x_
projected onto this plane. When the map is displayed, the up vector will point O:TlIJwW
toward the top of the screen.