站长说的很对,补充一下: ie[X7$@
Normal Vector xtCMK1#
x
The Normal Vector is a vector in 3D space that is used to orient the projection ]gX8z#*k
plane for the irradiance map. The plane is defined to be perpendicular to the {k=3OIp
Normal Vector, and the irradiance incident on the selected surface is projected CH(Y.Kj-
onto this plane. When the map is displayed, the normal vector is pointing toward y=pW+$k
you. MA_YMxP.'
Up Vector ?f9M59(l
The Up Vector is a vector in 3D space that is used to orient the projection plane Q_p&~ PNy5
for the irradiance map. The plane is defined so that the Up Vector is parallel to the v6DjNyg<x
vertical side of the plane. The irradiance incident on the selected surface is F3vywN1$,
projected onto this plane. When the map is displayed, the up vector will point O*/%zr
toward the top of the screen.