站长说的很对，补充一下： Bj k]ZU0T
Normal Vector pyLRgD0
g
The Normal Vector is a vector in 3D space that is used to orient the projection /| #&px)G
plane for the irradiance map. The plane is defined to be perpendicular to the { eCC$&"
Normal Vector, and the irradiance incident on the selected surface is projected Ox#\M0Wn$3
onto this plane. When the map is displayed, the normal vector is pointing toward O"Ku1t!
you. _^Mx>hb4.
Up Vector *Qugv^-
The Up Vector is a vector in 3D space that is used to orient the projection plane G!K ]W:m
for the irradiance map. The plane is defined so that the Up Vector is parallel to the }|PY!O
vertical side of the plane. The irradiance incident on the selected surface is ? A(QyaKz
projected onto this plane. When the map is displayed, the up vector will point nJ~drG }TD
toward the top of the screen.
