站长说的很对,补充一下: B*\$
/bk,
Normal Vector s\[LpLt
The Normal Vector is a vector in 3D space that is used to orient the projection &V'519vmoZ
plane for the irradiance map. The plane is defined to be perpendicular to the Ntb:en!X
Normal Vector, and the irradiance incident on the selected surface is projected qG<7hr@x]
onto this plane. When the map is displayed, the normal vector is pointing toward M!1U@6n!=)
you. [r)eP({
Up Vector |]`hXr
The Up Vector is a vector in 3D space that is used to orient the projection plane NXpmT4
for the irradiance map. The plane is defined so that the Up Vector is parallel to the w OI^Q~
vertical side of the plane. The irradiance incident on the selected surface is `@[l\.Vt:
projected onto this plane. When the map is displayed, the up vector will point Nln`fE/Ht
toward the top of the screen.