[Radiance-general] View-Up Vector

[Volker Hilsenstein]

Hello everyone,

I've got a quick question regarding the "view up"-vector:
as far as I understand, the -vd vector in  a view definition points
along the view direction (optical axis) of my virtual camera, whereas
the -vu points along the vertical (up) direction of my virtual camera.
So I guess they should be orthogonal. How does it affect
my view if I choose vu and vd such that they are not orthogonal
(Radiance only complains if  vd and vu are exactly parallel)  ?

Thanks,

Volker