viewpoint direction

[Jeff]

Vizard's built-in functions for determining what objects are in view include the window.pickRect command and window.pick command. You can use the viz.intersect command to see if a line segment intersects objects in the scene.

The yaw rotation of the viewpoint or tracker is not enough information to determine what object(s) are in view. You would also need the object and viewpoint positions to determine this. And if the user is looking up or down the object might be in line with their yaw rotation but not be in view. There is not a built-in function but you could probably use commands from the Python math library or Vizard's vizmat library to help do these calculations on your own. However I'm not sure why you would go this route since the pickRect and pick commands are an easy way to determine what objects are in view.