


       WELCOME TO THE OBJECT WORLD DEMO


Object World allows you to manipulated a three
dimensional scene using IDL's Object
Graphics. Object Graphics, IDL's object-oriented,
OpenGL-based graphics system allows rapid
interactive visualization of complex data without
expensive visualization hardware.

Click and drag with your mouse to manipulate
objects in the view. Because views are retained in
memory, re-rendering is virtually instantaneous.
While not necessary, if your system supports OpenGL
hardware rendering, IDL automatically takes
advantage of it, resulting in the fastest graphics
performance possible.

   CONTROLS
   --------
   <<Translate, Rotate and Scale>> Buttons
      Select the current mode of manipulation which
      will be applied to the currently selected
      object

   <<Add>> Button
      Add an object to the view.

   <<Add Child>> Button
      Add an object as a "child" of a currently
      selected object.  A child object gets
      selected along with its parent when the
      parent is selected.  Thus, a child will
      translate, rotate and scale along with its
      parent when such operations are applied to
      the parent.

   <<Delete>> Button
      Delete a currently selected object.  Deleting
      a parent object will also delete all its
      child objects.

   <<Select>> Button
      Select an object.

   <<Unselect>> Button
      Unselect all objects.  When no objects are
      selected you can rotate the checkered
      base-plate grid, and all the objects that are
      with it in a view, by clicking and dragging
      the left mouse-button

   MENUS
   -----
   <<File | load>>
      Load objects from a previously saved
      selection into the current scene.  After
      being loaded, the objects become the current
      selection.

   <<File | Save Selection>>
      Write an IDL save file with an objworld
      object in it.

   <<File | Print>>
      Print the objworld scene.

   <<File | Export VRML>>   
      Save the current view to a Virtual Reality
      Modeling Language (VRML) file.  VRML is a
      standard language for describing interactive
      3-D objects and worlds delivered across the
      Internet.  Be sure when viewing these images
      that your VRML browser supports the VRML 2.0
      format.  We have had good results using the
      CosmoPlayer 2.0, available free from
      http://cosmosoftware.com.

   <<File | Quit>>
      Close the Objworld program.

   <<Options | Drag Quality>> 
      Set the quality at which graphics will appear
      when being dragged or rotated with the
      mouse.

   <<Options | Show Grid>>
      Turn off or turn on the display of the
      "checkerboard" grid.

   <<Options | Anti-Alias>>
      Apply full-scene anti-aliasing.  This is
      most useful on 24-bit displays to provide
      smoother lines and polygon edges.

   <<Options | Manipulate Views>>
      Turn off or on a mode in which additional
      objworld views can be added.  Scale the views
      by clicking and dragging in their corners.
      Move the views by clicking and dragging
      them.
 
   <<Options | Copy to Clipboard>>
      Copy the current display to the system clipboard.

   <<About | About Object World>>
      Display this message.


   MOUSE BUTTONS
   -------------
   Note: On Windows platforms with a 2 button
   mouse, you can use <CTRL-Left mouse-button> to
   emulate the middle mouse-button.  On Macintosh
   computers hold down the Option key while
   pressing the mouse-button to emulate a "middle"
   mouse-button, or hold down the Command key while
   pressing the mouse-button to emulate a "right"
   mouse-button.

   Left Button:  
      Click and drag to manipulate a currently
      selected object.  If no object is currently
      selected, clicking and dragging will rotate
      all objects in a view.

   Middle Button:
      Click and drag to to rotate all ojects in a
      view.  

      Note that the use of a middle mouse-button is
      optional.  The same operation can be
      performed with the left mouse-button when all
      objects are unselected.

   Right Button:
      Click on objects to select them.  Re-click on
      selected objects to cycle through the
      Translate, Rotate and Scale manipulation
      modes.  Click in the background to unselect
      all objects.

      Note that the use of a right mouse-button
      is optional.  The same operations can be
      performed via the "Select", "Unselect",
      "Translate", "Scale", and "Rotate" GUI
      control buttons to the left of the scene.


   HOTKEYS
   -------
   Keyboard shortcuts:

      <spacebar> = select
      u = unselect
      s = scale
      r = rotate
      t = translate
      d = delete
      v = toggle view manipulation mode
   
