Rail Sweep

Sweep one or more curves along rails to create a 3D surface. This tool is a variation of the Sweep tool that uses two rails rather than one extrusion path.

Create a Rail Sweep

Create a new surface by sweeping one or more profile curves or surface edges along rails.

  1. On the ribbon, click the Surfaces tab.
  2. Click the Rail Sweep icon.

  3. Click one or more profiles, and then right-click to confirm.
    Attention: When the profile does not intersect the path, select Auto-alignment in the guide bar. Otherwise, no result is produced and a red exclamation mark appears in the Model Browser.
  4. In the guide bar, click Rail 1. In the modeling window, click the first rail.
  5. Rail 2 is automatically selected. Click the second rail.
  6. See Step 2 of Edit a Rail Sweep.
  7. Right-click and mouse through the check mark to exit, or double-right-click.

Edit a Rail Sweep

Modify the orientation, position, and shape of the rail sweep.

  1. Double-click the rail sweep.
    To Do this Note
    Reselect the profiles
    1. In the guide bar, click Profiles.
    2. Click the profiles you want to add or remove.
    3. Right-click to confirm.
     
    Change the selection method In the guide bar, select one of the following options:
    • Standard Selection
    • Chain Selection
    • Single Selection
     
    Reselect the rails
    1. In the guide bar, click Rail 1 or Rail 2.
    2. Click a rail.
    3. Right-click to confirm.
     
    Add or remove caps
    • To add caps to both ends, in the guide bar, click Caps.
    • To add or remove a cap from either end, click a red oval at either end.
     
    Auto-align the profiles See Auto-align the Profiles.  
    Define other options In the guide bar, click Options, and then select from the following options:
    • Arc Length Profiles: If the parameterization of the profiles is uneven, evenly space the isoparms of the surface between the profiles for a less stretched shape.
    • Arc Length Path: If the parameterization of the path is uneven, evenly space the isoparms along the path for a less stretched shape.
    • Extend: Extend the sweep surface the full length of the path, rather than being contained within the profiles. If only one profile is used, the sweep will always extend the full path.
    .
     
    Lock the direction In the guide bar, select Locked direction.  
    Add a vertex While holding down Alt, hover over a profile to snap to the profile, and then click.

    An added vertex is indicated by a blue circle.

    You can modify the shape of the loft by adding, deleting, and repositioning vertices on the profiles.

    The more vertices there are, the more control over the sweep.

    There are 3 types of vertices:
    • Original: These are the original vertices present in the profiles used to create the sweep.
    • Auto-added or Auto-deleted: Each profile must have the same number of vertices. The applications automatically adds or deletes vertices where needed.
    • User-added: These are the vertices that you added. They are displayed as crosses in the modeling views.
    Delete a vertex Click the vertex, and then press Alt+D.  
    Delete all added vertices Click a vertex, and then click Reset vertices.  
    Reposition vertices
    1. To select multiple vertices, use box selection.
    2. Drag to reposition the vertex or vertices.
     
    Create a seam point Click a vertex, and then click Make Seam.

    A seam point is indicated by a small solid triangle.

    You can only create seam points on a closed profile.
    Reposition a seam point Drag the seam point.  
    Invert the orientation of a profile Click a profile, and then click Invert orientation.

    The direction of the arrow on the profile or rail indicates its orientation.

    In most cases, the optimal orientation of each profile is internally calculated so that the resulting surface is not twisted. In some cases, inverting a profiles orientation will cause the sweep to fail.
    Modify the constraint See Modify the Constraint.  
  2. Right-click and mouse through the check mark to exit, or double-right-click.

Auto-align the Profiles

Use profiles for the sweep that do not intersect the rails.

Profiles are only used as reference. This option comes with extra parameters that allow more control over the position and orientation of each profile.

  1. Double-click the sweep to enter edit mode.
  2. In the guide bar, click the Auto-alignment option.
  3. In the modeling window, click a profile:
    • If only 1 rail was used:
      To Do this
      Reposition a profile on a point along the rail Type a value for Point on rail 1, and then press Enter.
      Reposition a profile on a point of the profile Type a value for Point on profile, and then press Enter.
      Rotate the profile around the rail's tangent Type a value for Rot. tangent, and then press Enter.
      Rotate the profile around the rail's normal Type a value for Rot. normal, and then press Enter.
      Rotate the profile around an axis that is perpendicular to the rail's tangent and normal Type a value for Rot. vertical, and then press Enter.
      Reverse the profile order along the rail Click Reverse profiles order.
    • If 2 rails were used:
      To Do this
      Reposition a profile on a point along the first rail, Type a value for Point on rail 1, and then press Enter.
      Reposition a profile on a point along the second rail Type a value for Point on rail 2, and then press Enter.
      Lock values for point on rail This option is enabled by default to move the profile along both rails. To disable click Lock values.
      Reposition a profile on a point of the profile Type a value for Point 1 on profile, and then press Enter.
      Reposition a profile on a point of the profile, Type a value for Point 2 on profile, and then press Enter.
      Swap values for Point 1 on profile and Point 2 on profile Click Swap values.
      Rotate the profile around the center line of the two rails Type a Profile rotation value, and then press Enter.
      Invert the direction of the second rail Click Invert rail 2.
      Reverse the profile order along the rail Click Reverse profiles order.
  4. Right-click and mouse through the check mark to exit, or double-right-click.