Simulink 3D Animation  Plane Take-Off with HUD Text  This model
is a variant of the vrtkoff example that shows also how to
display signal values as text in the virtual scene and a simple
Head-Up Display (HUD).  The text is sent to virtual scene using
the VR Text Output block. This block formats the input vector
using the format string defined in its mask (see sprintf() for
more information) and resulting string is sent to the 'string'
field of the associated VRML text node in the scene.  The HUD
behavior (maintaining constant relative position between the
user and the Text node) is achieved by defining a
ProximitySensor that senses user position and orientation as it
navigates through the scene and routing this information to the
translation and rotation of HUD object - in this case a VRML
Transform that contains the Text node.