TechDraw ProjectionGroup

    From FreeCAD Documentation

    TechDraw ProjectionGroup.svg TechDraw ProjectionGroup

    Menu location
    TechDraw → TechDraw Views → Insert Projection Group
    Workbenches
    TechDraw
    Default shortcut
    None
    Introduced in version
    -
    See also
    TechDraw View, TechDraw Section View

    Description

    The TechDraw ProjectionGroup tool creates a multiview projection of one or more 3D objects. The isometric views of the 4 front corners can also be included.

    If you only want to produce a single view, there is no advantage in using ProjectionGroup; you should then use Insert View instead. If you do not wish to use the traditional first- / third-angle projection, you should use multiple Views (Insert View) instead of ProjectionGroup.

    TechDraw ProjGroup example.png

    Three orthogonal views and one isometric view of a solid object

    Usage

    1. Optionally rotate the 3D view. The camera direction in the 3D view determines the initial value of the Primary Direction of the Projection Group (the DataDirection property of the central view).
    2. Select one or more objects in the 3D view or Tree view.
    3. If there are multiple drawing pages in the document: optionally add the desired page to the selection by selecting it in the Tree view.
    4. There are several ways to invoke the tool:
      • Press the TechDraw ProjectionGroup.svg Insert Projection Group button.
      • Select the TechDraw → TechDraw Views → TechDraw ProjectionGroup.svg Insert Projection Group option from the menu.
    5. If there are multiple drawing pages in the document and you have not yet selected a page, the Page Chooser dialog box opens: introduced in version 0.20
      1. Select the desired page.
      2. Press the OK button.
    6. The Projection Group task panel opens.
    7. Select which views should appear in the Projection Group, and the Projection Group's scale and other parameters.
    8. Press the OK button.
    9. Optionally move the Projection Group by dragging its central view.
    10. Optionally move the Projection Group's other views relative to the central view by dragging them individually.

    TaskProjGroup.png

    Projection Group task panel. The Primary Direction field indicates the current view direction.

    Properties

    Data

    Base

    • DataSource (LinkList): Links to the drawable objects to be depicted.
    • DataXSource (XLinkList): Links to the drawable objects in an external file.
    • DataAnchor (Link): The central view in the group. Normally the Front view.
    • DataProjectionType (Enumeration): First Angle or Third Angle.

    For the other properties in this group see TechDraw View.

    Collection

    • DataViews (LinkList): Links to the views in this ProjectionGroup.

    Distribute

    • DataAuto Distribute (Bool): If true, space out individual views automatically. Use false to position manually.
    • Dataspacing X (Length): Horizontal space between views when automatically positioned. Note that Scale and the size of other views in the group also influence the spacing.
    • Dataspacing Y (Length): Vertical space between views when automatically positioned.

    View

    Base

    See TechDraw View.

    Notes

    The ProjectionGroup as a whole inherits X, Y, ScaleType, Scale and Rotation from the basic View.

    Individual Views within the group inherit all part view properties, but the ProjectionGroup object controls the scale of all its member Views.

    The RotationVector property of individual Views within the group is deprecated as of v0.19. Use XDirection instead.

    Note that the central box displays the current projection direction of the primary view. It cannot be used to change the direction.

    Scripting

    See also: Autogenerated API documentation and FreeCAD Scripting Basics.

    A Projection Group can be created with macros and from the Python console by using the following functions:

    import FreeCAD as App
    
    doc = App.ActiveDocument
    cyl = doc.addObject("Part::Cylinder", "Cylinder")
    doc.recompute()
    
    page = doc.addObject("TechDraw::DrawPage", "Page")
    template = doc.addObject("TechDraw::DrawSVGTemplate", "Template")
    template.Template = App.getResourceDir() + "Mod/TechDraw/Templates/A4_LandscapeTD.svg"
    page.Template = template
    
    # Toggle the visibility of the page to ensure its width and height are updated (hack):
    page.Visibility = False
    page.Visibility = True
    
    group = doc.addObject("TechDraw::DrawProjGroup", "ProjGroup")
    page.addView(group)
    group.Source = [cyl]
    group.ProjectionType = "Third Angle"
    
    front_view = group.addProjection("Front") # First projection will become the Anchor.
    group.Anchor.Direction = (0, 1, 0)
    group.Anchor.RotationVector = (1, 0, 0)
    
    left_view = group.addProjection("Left")
    top_view = group.addProjection("Top")
    
    group.X = page.PageWidth / 2
    group.Y = page.PageHeight / 2
    
    doc.recompute()
    

    Note: The Projection Group should always be added to the Page, page.addView(group), before adding projections to the Group. This allows the Projection Group to use default parameter values derived from the parent page.