站长说的很对,补充一下: nQtWvT
Normal Vector gA+qC7=p$
The Normal Vector is a vector in 3D space that is used to orient the projection V/LLaZTE
plane for the irradiance map. The plane is defined to be perpendicular to the 2K6qY)/_
Normal Vector, and the irradiance incident on the selected surface is projected 18d4fR
onto this plane. When the map is displayed, the normal vector is pointing toward #u(^0'
P
you. R)(T^V`{
Up Vector B=T'5&
The Up Vector is a vector in 3D space that is used to orient the projection plane j'<<4.(
for the irradiance map. The plane is defined so that the Up Vector is parallel to the \0I_<
vertical side of the plane. The irradiance incident on the selected surface is f:,DWw`B
projected onto this plane. When the map is displayed, the up vector will point [{,T.;'<j
toward the top of the screen.