站长说的很对,补充一下: -/FCd(
Normal Vector N|Rlb5\
The Normal Vector is a vector in 3D space that is used to orient the projection LkNfcBa_
plane for the irradiance map. The plane is defined to be perpendicular to the ImvkB~8N
Normal Vector, and the irradiance incident on the selected surface is projected "qwRcuHY
onto this plane. When the map is displayed, the normal vector is pointing toward iVmf/N@A|
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Up Vector gS"@P:wYzs
The Up Vector is a vector in 3D space that is used to orient the projection plane (/FPGYu3h
for the irradiance map. The plane is defined so that the Up Vector is parallel to the s7&%_!4
vertical side of the plane. The irradiance incident on the selected surface is a0AIq44
projected onto this plane. When the map is displayed, the up vector will point <