站长说的很对，补充一下： x@)u:0
Normal Vector IU}`5+:m
The Normal Vector is a vector in 3D space that is used to orient the projection j.*}W4`Q_
plane for the irradiance map. The plane is defined to be perpendicular to the y.2 SHn0
Normal Vector, and the irradiance incident on the selected surface is projected 4RNzh``u
onto this plane. When the map is displayed, the normal vector is pointing toward C09@ 2M'
you. im"v75 tc
Up Vector <o
O_wS@:
The Up Vector is a vector in 3D space that is used to orient the projection plane o =}?aC3I
for the irradiance map. The plane is defined so that the Up Vector is parallel to the )1ciO+_
vertical side of the plane. The irradiance incident on the selected surface is Nt?B(.G
projected onto this plane. When the map is displayed, the up vector will point BVDo5^&W
toward the top of the screen.
