站长说的很对,补充一下: XnYX@p
Normal Vector A#`$#CO
The Normal Vector is a vector in 3D space that is used to orient the projection B|o@|zF
plane for the irradiance map. The plane is defined to be perpendicular to the WXo bh
Normal Vector, and the irradiance incident on the selected surface is projected sw9ri}oc
onto this plane. When the map is displayed, the normal vector is pointing toward 3Z~_6P^
+N
you. n3?
msY(*
Up Vector BW)@.!C
The Up Vector is a vector in 3D space that is used to orient the projection plane 1Y"9<ry
for the irradiance map. The plane is defined so that the Up Vector is parallel to the uNEl]Q]<e]
vertical side of the plane. The irradiance incident on the selected surface is aY4v'[
projected onto this plane. When the map is displayed, the up vector will point ;0|:.q
toward the top of the screen.