站长说的很对,补充一下: 3=
q,k<=L
Normal Vector q!O B?03n
The Normal Vector is a vector in 3D space that is used to orient the projection `"-ln'nw
plane for the irradiance map. The plane is defined to be perpendicular to the MB"TwtW
Normal Vector, and the irradiance incident on the selected surface is projected IQm[,Fh
onto this plane. When the map is displayed, the normal vector is pointing toward 7gx
7NDt
you. =.Hq]l6+
Up Vector .^F(&c*['
The Up Vector is a vector in 3D space that is used to orient the projection plane 4[ .DQ#r
for the irradiance map. The plane is defined so that the Up Vector is parallel to the CI}zu;4|
vertical side of the plane. The irradiance incident on the selected surface is B(zcoWQ*B
projected onto this plane. When the map is displayed, the up vector will point nG~#o
toward the top of the screen.