Sweep2 | Rhino 3-D modeling

The Sweep2 command fits a surface through a series of profile curves that define the surface shape and two curves that define the surface edges.

Steps

Select two curves as the rails.

Select cross-section curves in the order in which the surface will pass through them.

Note: Select open curves near the same ends. For closed curves, adjust the curve seams.

Tips

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Make the degree and structure of the rail curves match each other.

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Place cross-section curves so the endpoints are on the ends of the rails or on edit points of the rails.

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Turn on edit points and use Point object snap to place the section curves between matching edit points on the rails.

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If only one section curve is used, the entire length of the rails are used for the surface, regardless of the settings.

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Section curves can have differing structures. The surface takes the complexity of the most complex one.

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To use same shape curve in the whole sweep, with control over where the sweep ends, use the Orient commands to create a scaled copy of the shape curve and place its ends at the places on the rail curves where you want the sweep to stop.

Command-line options

ChainEdges (rails only)

Select connected edges based on the curve continuity of the connection between segments.

To chain-select objects

Inside a command that accepts chain selection, type chain.

Select first chain segment.

Chain options

AutoChain

Selecting a curve or surface edge automatically selects all curve segments connected with the level of continuity set by the ChainContinuity option.

ChainContinuity

Controls the level of continuity required between segments to be selected with the AutoChain option.

Direction

Forward

Selects curves in the positive curve direction.

Backward

Selects curves in the negative curve direction.

Both

Selects curves in both the positive and negative curve direction.

GapTolerance

If the gap between two edges/curves is less than this value, the chain selection will ignore the gap and will select the next segment.

AngleTolerance

When Continuity is set to Tangency, if the angle between two edges/curves is less than this value, the chain selection will consider the criteria for continuity met and will select the next segment.

Undo

Undo last segment selection.

Select next segment.

All

Select all segments.

Point (cross-sections only)

The Point option creates a surface that begins or ends at a point. Use this option only at the start or end of the curve series.

Drag seams to adjust (closed cross-section curves only)

Select a seam point marker, and move it along the closed curve.

Continue to adjust the seam points until they line with each other and the closed curves all have the same direction, and then press Enter.

Adjust seam options

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.

Sweep 2 Rail Options dialog box

Curve options

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.

Preserve first cross section

When you are matching edge tangency or curvature, your surface may pull away from your cross-section curves. This option forces the surface to match the first cross-section curve.

Preserve last cross section

When you are matching edge tangency or curvature, your surface may pull away from your cross-section curves. This option forces the surface to match the last cross-section curve.

Maintain height

Removes the association between the height scaling from the width scaling. By default, cross-section curves normally scale in both the height and width dimensions.

Off

Refit rails

Refits the rail curves before creating the sweep.

Edge continuity

Continuity is only enabled if the rails are surface edges and the shape curves are non-rational, that is, all control point weights are 1. Exact arcs and ellipse segments are rational.

Note: Only continuity options that the curve structure (point count and rational/non rational) supports will be available.

Position / Tangency / Curvature

Sets the continuity for the edge match.

Closed sweep

The Closed sweep option creates a closed surface, continuing the surface past the last curve around to the first curve.

Note: This option is only available after you select two cross-section curves.

Add Slash

Adds additional cross-section alignments to control how the surface is created between sections.