Table 1.

Viewing modes

Mode	Purpose
Statue	The viewer is fixed and the cut section is viewed by rotating about the line of intersection with the original z-plane. With non-zero pitch the effect of changing yaw will result in the section appearing to rotate.
Up-is-Up	A pre-defined or user-defined vector up is projected onto the cut section which is then rotated so that it will be parallel to the vertical axis on the user’s screen.
Fixed line	The fixed point used to define the centre of rotation can be coupled with a second fixed point to define a fixed line leaving one d.o.f. of rotation around that line.
Absolute	Unconstrained viewing mode where all angles must be defined explicitly.