View Invariance of The Sign of Instant
(2)
•
Rotation around X axis (tilt)
–
Use the same argument for pan. The distance
d
2
>0 ,
if the
tilting angle
φ
belongs to (-90º,90º)
•
Combine pan and tilt
together, the
camera can
rotate within the hemisphere,
and the sign of instant
remains the same
.