站长说的很对,补充一下: ImHU:iR[J-
Normal Vector FmI;lVF0j
The Normal Vector is a vector in 3D space that is used to orient the projection 4J}3,+
plane for the irradiance map. The plane is defined to be perpendicular to the Tf[dZ(+\
Normal Vector, and the irradiance incident on the selected surface is projected b1)\Zi
onto this plane. When the map is displayed, the normal vector is pointing toward [*HiI=
you. #Fzb8Yo
Up Vector ]]y[t|6
The Up Vector is a vector in 3D space that is used to orient the projection plane :rmauKR
for the irradiance map. The plane is defined so that the Up Vector is parallel to the QgZJ`G--
vertical side of the plane. The irradiance incident on the selected surface is 8A4TAT4,
projected onto this plane. When the map is displayed, the up vector will point C P&o%Uc*
toward the top of the screen.