站长说的很对,补充一下: (3x2^M8
Normal Vector W>CG;x{
The Normal Vector is a vector in 3D space that is used to orient the projection A]'XC"lS
plane for the irradiance map. The plane is defined to be perpendicular to the %dd B$(
Normal Vector, and the irradiance incident on the selected surface is projected [p0_I7
onto this plane. When the map is displayed, the normal vector is pointing toward E_D@7a
you. xOxyz6B\
Up Vector s}gdi
The Up Vector is a vector in 3D space that is used to orient the projection plane 4e[ 0.2?
for the irradiance map. The plane is defined so that the Up Vector is parallel to the +*qTZIXj
vertical side of the plane. The irradiance incident on the selected surface is H%>cpwa[7
projected onto this plane. When the map is displayed, the up vector will point BG-nf1K(
toward the top of the screen.