站长说的很对,补充一下: b};o:
Normal Vector A7|L|+ ?
The Normal Vector is a vector in 3D space that is used to orient the projection z,4 D'F&
plane for the irradiance map. The plane is defined to be perpendicular to the sx}S,aIU
Normal Vector, and the irradiance incident on the selected surface is projected 76KNgV)3
onto this plane. When the map is displayed, the normal vector is pointing toward wm_rU]
you. kX8NRPW
Up Vector d ez4g
The Up Vector is a vector in 3D space that is used to orient the projection plane =%7s0l3z
for the irradiance map. The plane is defined so that the Up Vector is parallel to the P,9Pn)M|
vertical side of the plane. The irradiance incident on the selected surface is RBBmGZ
projected onto this plane. When the map is displayed, the up vector will point ,>8w|951'
toward the top of the screen.