Viewpoint

Defines a means of viewing the scene. It specifies the camera position, orientation, and type. The description field can be used to provide a list of scene-provided viewpoints. There is only one Viewpoint active at any one time. All characteristics of the camera, including intrinsic camera motion are determined by Viewpoint. Motion under user control is determined by NavigationMode.

The position field determines the location in virtual space of the camera. There are no restrictions as to location.

The orientation field determines the orientation relative to the local coordinate system of the camera.

The camerType field determines the type of camera used at this viewpoint. It can be a perspective camera (default), orthographic camera, or stereo camera. A stereo camera projects two views of the scene into the display, one each for the left and right eyes.Other camera types may be provided by the viewing application.

Intrinsic motion of the Viewpoint is determined by the motion field. If the value of this field is 'none', then all motion is from the user and determined by NavigationMode. The value of 'turntable' rotates the object from right to left (clockwise looking down) with a sinusodial motion in Y according to the value of the Y-coordinate of position. The value of 'tilt' performs only the Y-axis motion. Other values may be defined by the application.