站长说的很对,补充一下: + bhym+
Normal Vector $WQq?1.9
The Normal Vector is a vector in 3D space that is used to orient the projection cFd
>oDS
plane for the irradiance map. The plane is defined to be perpendicular to the oSb, :^Wl
Normal Vector, and the irradiance incident on the selected surface is projected HHk)ZfWRo
onto this plane. When the map is displayed, the normal vector is pointing toward bBxw#_3A?E
you. 0pe3L
Up Vector 0Sl]!PZR1
The Up Vector is a vector in 3D space that is used to orient the projection plane L}{`h
for the irradiance map. The plane is defined so that the Up Vector is parallel to the OU DcY@x~
vertical side of the plane. The irradiance incident on the selected surface is H %f:K2
projected onto this plane. When the map is displayed, the up vector will point '8FC<=+p[
toward the top of the screen.