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    Mainfunction VWR (Viewer)
      The objects are displayed but cannot be modified.
    Mousefunctions
    Graphics
    Views / Viewports
    Hide / View

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    Mousefunctions

      Left mousebutton:
        select object or indicate position.
        With Ctrl-key pressed: suppress object-selection
          (do 3D-Rotation (see below) or start selection of group)

      Right mousebutton:
        select object AND call one of the functions for that object.
        With Ctrl-key pressed: suppress object-selection
          (activate a function for the group already selected)

      Select group:
        press Ctrl-key (and keep pressed);
        press left mousebutton (and keep pressed);
        drag mouse
        Clear group with Esc-key.

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    Graphics
    How to move, zoom, rotate the view:

    Moving                                 with Shift drag
       Press (and hold) the shift-key and move the mouse.
       No mouse button.

    Zoom in/out                         with Control + Shift drag
       Press and hold the Shift-key and the Ctrl-key and move the mouse.
       Moving from left to right causes the image to enlarge.
       Or using the mousewheel.

    3D rotation                                    with Ctrl drag
       Press (and hold) the Ctrl-key and move the mouse.
       Horizontal movement of the mouse rotates the part in the image
         plane (the center of rotation is always the screen center).
       Vertical movement of the mouse tilts the part in the image
         plane.

    Define the display center:
       Enable checkbox RotCen and select the new center
         - Select a vertex or
         - Select a free point (Ctrl drag, pick then a red point)

       The currently active layer for interactive rotation is
         indicated by a yellow rectangle.
       The Z-plane of the view can also be set by entering the new
         Z-value in the box (next to the button STEP);
         conclude with a return.

    Scal.All - Button:
       Display all objects (sets focus and zoom).

    Scal.Fix - Button:
       Setting a fixed, pre-enlargement,
       according to the value of MODSIZ (approximate maximum size
         of the model).
       Change MODSIZ by function MODSIZ Standards/Tolerances/Modelsize,
         or by Command MODSIZ {value}

    Define representation accuracy for circles, ellipses, curves:
        Standards/Tolerances (in the menu bar above)
        Change the Modelsize, 'Modify'.
          This will automatically derive the tolerances and
          the whole model is immediately recalculated.

        The Modelsize directly affects all tolerances;
         - The poligonalisation-tolerance
         - Identical-point tolerance
         - The Model size in the export of mockup models (eg VRML)

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    Predefined views:

    TopView   - top view  (view X-Y)
    FrontView - side view (view X-Z)
    SideView  - side view (view Y-Z)
    AxoView   - Axonometric View

    Viewport:      save / restore the current viewport

      Save with keys Ctrl-"V".
      The number of Viewports is unlimited.
      Loading a new model clears all stored viewports.

      Restore the last stored viewport with keys Ctrl plus cursor-right.

      Restore the previous stored viewport with keys Ctrl plus cursor-left.

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    Hiding individual objects: see box Hide, View
    Hiding objects Group: see box Hide, View

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