站长说的很对,补充一下: ~@3X&E0S
Normal Vector Bt8
The Normal Vector is a vector in 3D space that is used to orient the projection Z+zx*(X
plane for the irradiance map. The plane is defined to be perpendicular to the ;:w?&4
Normal Vector, and the irradiance incident on the selected surface is projected 7y4!K$c$
onto this plane. When the map is displayed, the normal vector is pointing toward Z+mesj?.
you. F?+K~['i
Up Vector Sdc
yL%6!
The Up Vector is a vector in 3D space that is used to orient the projection plane ~"<AYJlO
for the irradiance map. The plane is defined so that the Up Vector is parallel to the sj)$o94=
vertical side of the plane. The irradiance incident on the selected surface is s'&/8RR
projected onto this plane. When the map is displayed, the up vector will point qqm7p
,j
toward the top of the screen.