站长说的很对,补充一下: [\eVX`it
Normal Vector Yj bp:
The Normal Vector is a vector in 3D space that is used to orient the projection 1_!?wMo:f
plane for the irradiance map. The plane is defined to be perpendicular to the fD(r/~Vu
Normal Vector, and the irradiance incident on the selected surface is projected 6`6 / 2C$%
onto this plane. When the map is displayed, the normal vector is pointing toward i?b9zn
you. 04}8x[t
Up Vector 21Dc.t{
The Up Vector is a vector in 3D space that is used to orient the projection plane LauGT* z!
for the irradiance map. The plane is defined so that the Up Vector is parallel to the ;!VxmZ:j[
vertical side of the plane. The irradiance incident on the selected surface is S:i#|T."
projected onto this plane. When the map is displayed, the up vector will point YL!{oHs4
toward the top of the screen.