Sweep

The Sweep command fits a surface through a series of profile curves that define the surface cross-sections and one curve that defines a surface edge.

• Sweep curve
• Command-line options

Sweep curve

Steps:

1. Select a single rail curve.
2. Select cross-section curves in the order that the surface will pass through them.
   When multiple closed cross-section curves are selected, there will be an extra step for adjusting curve seams.
3. When you are satisfied with the results, Click OK to close the dialog.

Sweep Rail Options

Frame style

A frame is a 3D point and three direction vectors. It can be drawn as something that looks like the Rhino world axes icon. It describes a unique coordinate system in space. Frames are calculated along the rail and are used to orient the cross-section curves at those locations. In a simple case with one cross-section, frames are made at the cross-section curve location and where the calculated cross-section is going to go. The 3-D rotation between those two frames determines the rotation of the cross-section curve at its new location.
Freefrom is the default Frame style. The selected Frame style will be remembered in the current Rhino for next use.

• Freeform
  The cross-section curve rotates to maintain its angle to the rail throughout the sweep.
• Roadlike
  Specify an axis for calculating the 3D rotation of the cross-section.
  The default Roadlike axis will be different depending on the rail curve. For a planar rail curve, the default axis is perpendicular to the curve plane. For a non-planar rail curve, world-Z axis will be used.
• Set axis Sets the axis direction for the Roadlike style.
• Align with surface (surface edge as rail only)
  If the rail is a surface edge, the cross-section curve will twist with the surface edge. If the shapes are tangent to the surface, the new surface should also be tangent.

Sweep options

• Closed sweep
  Creates a closed surface, continuing the surface past the last curve around to the first curve.
  This option is only available after you select two cross-section curves.
• Global shape blending
  The sweep is linearly blended from one end to the other, creating sweeps that taper from one cross-section curve to the other.
  Otherwise, the sweep stays constant at the ends and changes more rapidly in the middle.
• Untrimmed miters
  If the sweep creates a polysurface with kinks, the component surfaces will be untrimmed.

Curve options

• Refit rail
  Refits the rail curve before creating the sweep.
• Align cross sections
  Allows reversing the direction of the cross-section curves.

• Do not change cross sections
  Creates the sweep without altering the cross-section curves.
• Rebuild cross sections with ___ control points
  Rebuilds the cross-section curve's control points before creating the sweep.
• Refit cross sections within ___
  Refits the cross-section curves before creating the sweep.

Command-line options

ChainEdges (rails only)
Select connected edge/curve segments based on the continuity between segments.

Point (cross-sections only)
Creates a surface that begins or ends at a point.

Adjust seam options (closed curves only)

• Flip
  Reverses the curve direction.
• Automatic
  Attempts to align the seam points and directions without intervention.
• Natural
  Moves the seam points to the way they were at the beginning of the command.
• SnapToKnots
• Yes The seam points are always at the knots. You can only move them among the knots.
• No The seam points may leave the knots. You can move them without restriction.