##

##

    First Steps CAD - documentation gCAD3D

    Mainfunction CAD
      Interactive creation and modification of objectcodes.
      Select the CAD checkbox.

    How to move, zoom, rotate the view
    How to operate CAD

    Create objects:
     Construct wireframe elements
     Construct surfaces
     Construct a CompositeCurve
     Cylinder/prism design
     Create assembly
     Load bitmap
     Activity

    Modify objects:
     Modify existing points
     Trim a line
     Mirror a line

     Construct wireframe elements

     A slotted hole design:
     Select main module CAD;

     Select CAD feature “CIR Cen Radius";
     Define the center point (left mouse button in the graphics window),
     key the radius,
     move to the next input field with the cursor-down button or the tab-button,
       (not return);
     Z-axis input vector (DZ is predefined);
     You will see the circle now;

     Modify:
      Esc key deletes the contents of the input field;
      Cursor-down key: new preview of the object.

     Save the object:
      Create the object with OK button, return-key or right mouse button "OK".
      You can inspect the object code (text) with function MAN.

     Create a second, adjacent circle.

     Produce tangents to the 2 circles:
       activate CAD-function "LN tangent";
        Select the two circles,
        If necessary, select the next version with the PageDown-button,
          go back with picture-up-button;  "2" provides second solution.
        Save object.

      Get intersectionpoint line circle:
        ( used later as startpoint / endpoint of contour)
        activate CAD-function Trim intersect / "INT (intersect)"
        select circle
        select line
        Save object (the intersection-point).

      Create a closed contour:
        activate CAD-function Curves / "S Contour"
        select the intersection-point,
        select all contour-objects in counterclowise order (or use the "REV" button)
        select the intersection-point (endpoint),
        Save object.

      Create surface from closed contour:
        activate CAD-function Surfaces / "A Planar Surf"
        select the contour
        Save object.

     File the model:
        activate File/save Model as/gcad
        key "Test1"
        button SAVE

     The model is saved as file Test1.gcad in the active output directory.
     You can view/modify this file with any text editor.

     Export as DXF
      File/save Model as/DXF ..

    Constructing surfaces

    To construct a surface, the outer-contour is required.
    Inside the outer-contour can be internal-contours (holes).

    The contours must be closed.
    For contours can be used circle, ellipse, closed-polygon or closed CCV.

    Create the contours:
      create a circle
      create a second circle inside the first circle (a hole)

    Create the surface:
      Select CAD-function "A planar Surface"
      Select the outer contour and all inner contours.
      Save object (right mousebutton).

    VRML Export:
     Surfaces can be saved as a VRML file;
     File/save model as / VRML2 or VRML1

    Constructing a CompositeCurve

    You can connect curves of different types to a contour.
    You do not have to trim the individual parts.
    The first and the last inputobject should be a point,
      internal points can be used.

    CAD-function "S Contour (CCV)"
     select the startpoint
     Select all contour elements
       remove an invalid selection: Use the delete button in the LineEdit window.
       turn direction (eg circle): select "CW" (in the LineEdit window)
     select the endpoint
     Save object (right mousebutton).

    See also CAD-CCV

    Constructing a cylinder/prism

     For prisms (as for a surface) a closed contour is required.

     CAD-function "B Prism Base Thick"
     Select contour (eg S20);
     Enter thickness "50") or
     Enter Z-vector ("D(0 0 50)") or
     Define a point ("P(0 0 100)") - generates a cone

     Preview with cursor-down key
     Save object (right mousebutton).

     Create an Assembly

     An assembly consists of loaded and positioned Sub-models.

     A sub-model can be placed by:
      - Origin [and an X-and Z-axis] or
      - Origin and a reference system (a plane (PLN, "R"))

     Clear model Space:
      File/New.

     Load / use external models (native models (.gcad), mockup models (.wrl .obj):
      CAD-function "M ext.Model Filename Pos'
      Input 'Filename': Push middle mouse button (in the graphics window),
       Select a model file,
       or - if the Model is already loaded - select model.
      Position (select the input field for 'Position' or the cursor-down key):
       indicate position in the graphics window with the left mouse button
        or key in, eg. "P(100 100 100)"
      Z-Axis (optional):
       Default is "DZ" (must be entered when an X-Axis is defined).
    	 All the text entries must be without apostrophes!
      X-axis (optional):
       Default is DX, "DY" rotates the model 90 degrees,
       "D(1 1 0)" (a reference vector) rotates by 45 degrees.
      Save object (right mousebutton).

      Load native Models into the active model:
       subModels / load Submodel from File
       Load the desired model
       (is created as an internal model, is not yet visible)

      Use internal Model:
       CAD / 'M int.Model'
        'Sub-model': middle mouse button (in the grafic window) - select model
        ..

      Load STEP, IGES, DXF models as sub-models:
       Must currently first be loaded directly (File/Open Model),
       then be filed in native format (.gcad)
       can now be used as subModel ..

    Load bitmap

      Bitmaps can be displayed simultaneously with 3D objects;
      Bitmaps are always shown normal to the view surface.
      Files with format .JPG and .BMP can be imported.

     Load Bitmap:
      Select CAD function 'N Image Pos Filename'
       'point image':
         give the lower left position of the bitmap
       'StartPoint Line' optional:
         if you want a line to the image:
         Select the start point of the reference line
       'Linetype'   optional:
         1 = full, 2 = dashed, 3 = dash-dot
       'Filename':
         use middle mouse button to select a bitmap-file
       'Scale'    optional:
          0.2 gives Image reduced to 20% of original

      View with the cursor-down button.
      Save object with right mouse button.

      If no scale (or value 0) is defined, then the bitmap is dynamically scaled.
      Where there is a scale, this scale is fixed.

    Activity

      Any CAD object can be linked to an interaction, eg:
       - move View position (to a predefined view position)
       - load a predefined model (such as HTM HREF)
       - run a supplementary program (DLL)

      Interaction is active in mode VWR, and inactive in modes CAD and MAN.
       (in CAD or MAN activate with Options/Interaction).

    Create Activity 'change view position':
      Select CAD-function 'Interact connect'
       'connect object':
          select an object (selection of this object will activate the view-change)
        'command':
          Now set the desired View position (zoom, pan ..)
          Now select Insert/viewport (from the top menu bar),
          - the View parameteris are written into the input field.
      Save object (right mousebutton).

    Test Activity:
      select main mode VWR and pick the object.

    Create Activity 'Load model':
      Select CAD-function 'Interact connect'
      'connect object':
        select an object (selection of this object will activate the view-change)
      'command':  enter:
        LDMOD Data/sample_mod_blech1.gcad
      Save object (right mousebutton).

      This has generated the following code:
       I20 = N20 "LDMOD Data/sample_mod_blech1.gcad"
        (where N20 is the activating object, the model "Data/sample_mod_blech1.dat"
        is loaded with the selection of N20).

      Before the test, Save to File/save Model or Ctrl-S.

    Create Activity 'Start program':
       Enter 'command':
         EXECM DemoKondensatorplatte

       This will load the library DemoKondensatorplatte.so (.dll in MS-Win)
       and start the function gCad_main.
       For details, see .. /doc/gCAD3D_prog_de.txt.

    See also model sample_activ_1.dat

    Create a tag with the text "Exit"
       Select CAD function 'N TAG type, line, text'
       'Type + Color'
         Enter "23" (without quotation marks) to make a block of colour green; For details, see documentation
       'TextPoint'
         defines the left middle of the text block
       'Start Point', 'Line' and 'Linetype'
         remains' empty - no connecting line
       'text'
         "Exit" (without quotation marks).

    Modify existing points

    Finish the active CAD-function with the Esc-key.
      (several times if inputfields are not empty).

    Modify existing point:
      select point with right mousebutton,
      select function "move points".
      Move mouse, select new position (with left mousebutton),
      save with right mousebutton.

    Modify points of line or curve:
      select object with right mousebutton, select "move points".
        Select the point to move (yellow rectangle).
          Move mouse, select new position (with left mousebutton),
        Select next point to move or save with right mousebutton.

    For detailed info see  PED_en.htm

    Trim a line

    - create 2 crossing lines:
      select "LN PT PT", indicate 2 points, press right mousebutton.

    - create the intersectionpoint:
      select "INT(intersect)", select both lines, press right mousebutton.

    - trim line:
      select "CUT(trim)", select the line to trim, select the point,
      select alternate version if necessay:
        click into field "[solutionNr]", key PageDown (twice),
      press right mousebutton.

    Mirror a line

    - create mirror-plane:
      select "PLN PT Z-Axis", indicate the position of the plane,
      define the Z-axis (eg select or key "DY"),
      press right mousebutton.

    - mirror line:
      select "Mirror obj", select the line, select the plane,
      press right mousebutton.

    Send bug-reports, suggestions for improvement to
      franz.reiter@cadcam.co.at