站长说的很对,补充一下: mADq_`j
Normal Vector 540-l Me
The Normal Vector is a vector in 3D space that is used to orient the projection /Q8E12
plane for the irradiance map. The plane is defined to be perpendicular to the $0~H~-
Normal Vector, and the irradiance incident on the selected surface is projected 4RGEg;]S
onto this plane. When the map is displayed, the normal vector is pointing toward rzsb(
you. bx_`S#*N
Up Vector K*xqQ]&
The Up Vector is a vector in 3D space that is used to orient the projection plane ~k'KS
7c
for the irradiance map. The plane is defined so that the Up Vector is parallel to the I6,'o)l{_
vertical side of the plane. The irradiance incident on the selected surface is */;[ -9
projected onto this plane. When the map is displayed, the up vector will point m-dyvW+
toward the top of the screen.