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    Documentation application 3D_from_2D

    The application allows you to create 3D curves by selecting
      Points on pixel images.
    3-D surfaces can be generated from the 3D curves with CAD standard-functions.
    There are 1 or 2 or 3 view images required.
    The view images (formats. .jpg or .bmp) should have a view from above
    and / or a side-view or front-view.

    Program call:
        Start the user application "3Dfrom2D"
         - Select from the list of additional applications or
         - If application was active before: start with Ctrl-P.

    Exit the application:
      Exit button or Ctrl + Esc.
      All data will be passed to the CAD model.

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    Setup:
      Top-view / Side-view / Front-view
      Scale
      Offset
      Angle
      X-lines
      Y-lines
      Z-lines

    2D to 3D:
      import CAD Point
      import CAD-plane
      Point
      Polygon
      Spline
      Circle                           not yet implemented
      Plane

    3D
      Delete
      MirrXZ
      MirrYZ

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    Setup:

    to prepare:
      - Images (jpg's) of one, two or three views.
      - Photos must be equalized
        Editing images with Gimp for example:
        - Equalizing with: Tools / Transform / Perspective
        - Cut with: Tools / Transform / Crop
      - 90-degree turns should be made with the image editing program
        Gimp: Image / Transform / Rotate 90 degrees
      - Very large photos (over 4000 pixels - depending on the graphics card)
        should be reduced with an image editing program.

      Top / Side / Front View
        Definition of images (selected from file list).
        Top view: contains horizontal X-axis, vertical y-axis.
        Side view: contains horizontal X-axis, vertical Z-axis.
          Located above the top view.
        Front view: Z-axis has horizontal, vertical Y-axis.
          If the right of the top view.

        ^ Z
        |-----+
        | Side |   X
        +-----+---->

        ^ Y ^ Y
        |-----+          |------+
        | Top |    X     | front | Z
        +-----+---->     +------+---->

        After the definition of the view images, the zero points of the
        three basic axes must be defined -
        - Click into view images,
          click again to indicate horizontal or vertical.
        The base levels will be shown as red lines.

      X-lines
        Generating one or two horizontal guides in
        Top view or side view. Esc = Delete last.

      Y-lines
        Generating one or two vertical guides in
        Top view or side view. Esc = Delete last.

      Z-lines
        Generating one or two guidelines in
        Side view or front view. Esc = Delete last.

      Scale
        Select the input corresponding to the view;
          change the values with the cursor keys up / down.

      Offset
        Select the input corresponding to the view;
          change the values with the cursorkeys left / right or
          up / down.

      Angle
        Select the input corresponding to the view window;
          change the values with the cursorkeys left / right.

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    2D to 3D:
      Create objects. Objects will be displayed in 2D-space;
        when the application exits all objects will be copied into 3D-space.

      import CAD Point
        Creates 2D-points of points or end points of curves.
        Use it to generate curves.
        Select a CAD-point or CAD-curve.

      import CAD-plane
        Generates 2D-planes  of 3D-CAD-planes
        Use it to generate curves.
        Select a CAD plane.

      Plane
        First create all planes at which curves or
          common points are located.
        Planes are shown as red lines.
        Create a plane through the selection of 2 points in one view;
          The second point is used to define horizontal or vertical.
        Top view - horizontal: an X-Z plane.
        Top view - vertical: a Y-Z plane.
        Side view - horizontal: an X-Y plane.
        Side view - vertical: a Y-Z plane.
        Front view - horizontal: an X-Z plane.
        Front view - vertical: an X-Y plane.
        Esc clears last created level.

      Point
        If several curves have a common point, first this point
          should be created; afterwards use this point.
        Select the point in 2 different views.
        If the point is on a plane, select the plane
          for the second view (2D-plane or CAD-plane).
        Esc clears last point created.

      Polygon
      Spline
        Select all points of the curve in a view, then
          (In reverse order) in a different view.
        Esc clears the last selected point.
        If an item is out of a photo: indicate the position in the
        corresponding height inside the photo.
        If a point is on a plane, the plane should be selected.
        If the entire curve lies in a plane, select the plane
          for the second view (2D-plane or CAD-plane).

      Circle                not yet implemented

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    3D:
      Preview of all up to now created objects in 3D-space.

      Delete
        Delete 2D objects.
        Select the object.

      MirrXZ
        Flip an object around the X-Z plane.
        Select the object.

      MirrYZ
        Flip an object around the Y-Z plane.
        Select the object.

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    Send bug reports, suggestions for improvements to
    support@gcad3d.org

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