Transitioning from 2D to 3D AutoCAD drawings 103

Continuing with my “Transitioning from 2D to 3D” series, I’ll use the existing single-line beams as paths for sweeping the beam profiles. The SWEEP command enables you to create a solid or surface by sweeping an open or closed planar curve (profile) along an open or closed 2D or 3D path. If you sweep an open curve, AutoCAD will create a surface. If you sweep a closed curve, AutoCAD will create a solid. Since beam profiles are not typically included in plan drawings, I copied them from the 2D Framing Elevation. See Commandless Copy for more for information on coping objects between drawings.

The beam profile that I copied was a block. Before using the SWEEP command, I had to explode the block so I could access the closed polyline, which represents the cross-section of the beam.

From the Dashboard, choose Sweep to launch the SWEEP command.

1. Select the closed polyline, which represents the beam cross-section and then press enter to finish the selection set.
2. Select a line that represents a beam in the structural plan. AutoCAD automatically aligns the profile so that it is perpendicular to the path and it uses the centroid of the profile as the basepoint to follow the path. You can change the default behavior using the Alignment and Basepoint options from the right-click menu.
3. Repeat the SWEEP command using the same profile for each of the beam lines. Hint: Ensure that you have set AutoCAD to “Retain defining geometry”. See my previous post for more information.

The SWEEP command does not allow you to select multiple paths so you will have to perform this operation multiple times. However, you can use the AutoCAD API (Application Programing Interface) to automate the SWEEP command. Or, if the single line beams were inserted as blocks similar to the columns, you would only have to use the SWEEP command one time for each different block definition.

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