站长说的很对,补充一下: z7_./ksQ
Normal Vector S- H3UND"
The Normal Vector is a vector in 3D space that is used to orient the projection eo8 0L
plane for the irradiance map. The plane is defined to be perpendicular to the p~b$+8#+
Normal Vector, and the irradiance incident on the selected surface is projected Sce9R?II
onto this plane. When the map is displayed, the normal vector is pointing toward :W&\})
you. h`Mf;'P
Up Vector `WT7w']NT
The Up Vector is a vector in 3D space that is used to orient the projection plane Q4PXC$u
for the irradiance map. The plane is defined so that the Up Vector is parallel to the wf4Q}l2,d
vertical side of the plane. The irradiance incident on the selected surface is {8MF!CG]
projected onto this plane. When the map is displayed, the up vector will point G~]BC#nB_
toward the top of the screen.