站长说的很对,补充一下: |2RoDW
Normal Vector t
Qo)* z
The Normal Vector is a vector in 3D space that is used to orient the projection aumWU{j=
plane for the irradiance map. The plane is defined to be perpendicular to the +xoh=m
Normal Vector, and the irradiance incident on the selected surface is projected K1y]
onto this plane. When the map is displayed, the normal vector is pointing toward !O|d,)$q
you. J,N='~kfh
Up Vector QuFzj`(
The Up Vector is a vector in 3D space that is used to orient the projection plane k;EG28
for the irradiance map. The plane is defined so that the Up Vector is parallel to the ,Dh+-}
vertical side of the plane. The irradiance incident on the selected surface is 0,a/t
jSr
projected onto this plane. When the map is displayed, the up vector will point scr`] tD
toward the top of the screen.