<viewpoint> ‐ A viewpoint
This element defines a viewpoint inside a scene graph. There can be several viewpoints inside a scene. Each active window is associated with a unique user. This user has a current viewpoint chosen among the viewpoints defined in the current scene and the base viewpoint (a default viewpoint located at the origin). The viewpoint of each user can be modified interactively through user interaction, through a definition of successive shots in the configuration file (see environment node), or through the script commands set_current_viewpoint and set_viewpoint.
The string value of the type attribute is equal to orientable in the case of a camera that can be freely oriented, and to lookat in the case of a look-at camera bound to a scene node.
For each active user (each user associated with one window), there is only one single active viewpoint at a time. User can interactively change the active viewpoint through predefined commands as described in Section 3.2.2.
None.
The example below defines a viewpoint named camera_#1 that looks at the node named locutor and has (0,1,0) for vertical axis.
<viewpoint id="camera_#1" type="lookat" xlink:href="#locutor" x="0.0" y="1.0" z="0.0"/>