Offset Geometry

Use the Offset tool to offset surfaces, solids, lines, elements, or faces.

Note: This functionality is not supported for FE geometry.
  1. From the Topology ribbon, click the Offset tool.


    Figure 1.
  2. Set the guide bar selector to Lines, Surfaces, Solids, Elements, or Faces.
    Option Description
    Lines
    1. Select free lines to offset.
    2. Click on the guide bar and define the following options:
      Link type
      Choose how the offset is generated when there is a discontinuity (other than 180 degrees) in the direction of the curvature of the input line list, that is, when input lines do not connect with each other.
      interpolate
      Interpolate the offset direction on both sides of the discontinuity to allow a smooth transition. In this case, along the interpolation region, the offset direction will be different than the curvature direction. Amplified fluctuations, which would occur in the offset because of small ripples in the input curve, are smoothed out with this option.


      Figure 2.
      insert link
      Insert a straight line segment as a link between the offset of input lines, if there is a jump in offset direction at points where the input lines meet.
      Figure 3.

      no link
      Do not insert a link if there is a jump in offset direction at points where input lines meet. In this case, the offset lines may become disconnected.
      Figure 4.

    3. Enter an offset distance in the microdialog. Use the icons to toggle between a uniform offset or a linear offset based on a start and end value.
    4. Optionally, you can choose to switch the starting point of the line list or delete the original lines after offsetting on the guide bar.

      The start of the line list is indicated by a red arrow at the end of the chain.

    Note:
    • Closed lines are treated as if they were not closed so that the offset creates open lines.
    • Successive offsets (4-5 offsets, one after other) or very large offset values of some lines become sensitive to approximation errors or invisible fluctuations in the line.
    Surfaces and Solids
    1. Select surfaces or solids to offset.
    2. If desired, select Continuous offset on the guide bar to preserve the connection between adjacent surfaces after offsetting. For surfaces, you also have the option to define separator lines.
    3. Click-and-drag to offset or enter a value in the microdialog.
    Note: The topology of the surface edges (free, shared edges, and so on) is maintained during the offset function. Some individual surfaces will be trimmed or extended to maintain the connectivity.
    Elements and Faces
    1. Select elements or faces to offset.
    2. Click on the guide bar and define the following options:
      Layer type
      Solid, Thicken shell, shell, and shell offset.
      Thickness method
      Total thickness/Offset Distance: specify the total thickness of the layers of solid elements you want to create or specify a fixed distance to move the elements in case of shell offset.
      Element thickness: Thickness is parsed from Nodal/Element thickness defined in the Entity Editor.
      Element size: thickness value is parsed from Preferences > Meshing > Element > Default size.
    3. Click-and-drag to offset or enter a value in the microdialog.
    4. Define the number of layers.
    5. Optionally, click to define the corner type.
    6. Optionally, click to reverse the direction.
  3. On the guide bar, click one of the following:
    • - Apply and stay in the tool
    • - Apply and close the tool
    • - Exit the tool without applying
Tip: Offset geometry in the opposite normal direction by entering a negative offset value.