站长说的很对,补充一下: @4sEHk
3
Normal Vector T}fH
The Normal Vector is a vector in 3D space that is used to orient the projection WFHS8SI
plane for the irradiance map. The plane is defined to be perpendicular to the /hrVnki*
Normal Vector, and the irradiance incident on the selected surface is projected ~>2DA$Ec
onto this plane. When the map is displayed, the normal vector is pointing toward [[vu#' bc
you. 8ckcTNPu
Up Vector T2EQQFs
The Up Vector is a vector in 3D space that is used to orient the projection plane UXs=7H".
for the irradiance map. The plane is defined so that the Up Vector is parallel to the h\qQ%|X
vertical side of the plane. The irradiance incident on the selected surface is 6f=,$:S$
projected onto this plane. When the map is displayed, the up vector will point *=yUs'brB
toward the top of the screen.