站长说的很对,补充一下: ESY\!X:|
Normal Vector ]%6XE)
The Normal Vector is a vector in 3D space that is used to orient the projection m@`
NN
plane for the irradiance map. The plane is defined to be perpendicular to the nxx&aq(._
Normal Vector, and the irradiance incident on the selected surface is projected "&TN}SBW
onto this plane. When the map is displayed, the normal vector is pointing toward d+6-ten
you. MM/D5g
Up Vector S4>1 d-
The Up Vector is a vector in 3D space that is used to orient the projection plane D"s
]dQ$r
for the irradiance map. The plane is defined so that the Up Vector is parallel to the ;LFs.Jc<
vertical side of the plane. The irradiance incident on the selected surface is "xMnD(p
projected onto this plane. When the map is displayed, the up vector will point uPL|3ACS
toward the top of the screen.