Twist
Turns the perspective view in the viewing plane as if you are watching the scene while tilting your head to the side.
Twist can be used only in a Perspective window. It is always relative to the current position.
Access this tool from the View palette:
To tilt the drag with the mouse, or type the twist angle and press Enter.
Dragging the mouse to the right rotates the view counter-clockwise, and dragging to the left rotates the view clockwise. Dragging across the whole window rotates the view 360 degrees.
Twist Options
Eye/View/Up
These sliders let you define a view by moving the camera.
The Eye position, View point position, and Up vector end point determine the view. The nine fields that define these positions contain decimal numbers. They represent, from left to right, the X, Y, and Z Coordinates for each of the three camera parameters.
To see the camera as you modify it, use WindowDisplay > Toggles > Cameras 
.
Zoom
The Zoom slider also takes a decimal number that defines the extent of the field of view of the camera in degrees. Values must be positive in the range of 0.2 to 179.
Twist workflow
To tilt the drag with the mouse, or type the twist angle and press Enter.
Dragging the mouse to the right rotates the view counter-clockwise, and dragging to the left rotates the view clockwise.
Dragging across the whole window rotates the view 360 degrees.