The next few commands help you define a line and its direction. Each of these commands requires you to choose a start point for your line before you can specify the line direction. You can specify your start point by physically choosing a location, using an Osnap, or using one of the point-related line commands discussed earlier.
Many of these line commands require a line or arc and will not work with a polyline. Those commands include Create Line By Sideshot, Create Line By Extension, Create Line From End Of Object, Create Line Tangent From Point, and Create Line Perpendicular From Point.
Create Line By Bearing Command
The Create Line By Bearing command is one of the most commonly used line-creation commands.
This command prompts you for a start point, followed by prompts to input the Quadrant, Bearing, and Distance values. You can enter values on the command line for each input, or you can graphically choose inputs by picking them onscreen. The glyphs at each stage of input guide you in any graphical selections. After creating one line, you can continue drawing lines by bearing, or you can switch to any other method by clicking one of the other Line By commands on the Draw panel.
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The tooltips for a quadrant (top), a bearing (middle),
and a distance (bottom) |
Create Line By Azimuth Command
The Create Line By Azimuth command prompts you for a start point, followed by a north azimuth and then a distance.
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| The tooltip for the Create Line By Azimuth command |
Create Line By Angle Command
The Create Line By Angle command prompts you for a start point, an ending point to establish a backsight direction, a turned angle, and then a distance. By default, this command assumes the angle-right surveying convention (clockwise from starting direction). However, an option to turn counterclockwise is offered at the command line if needed.
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| The tooltips for a turned angle (top) and a distance (bottom) for the Create Line By Angle command |
Create Line By Deflection Command
By definition, a
deflection angle is the amount of angular deviation (usually measured clockwise) from a backsight direction. In other words, 180 added to a given deflection angle would be an equivalent angle-right. When you use the Create Line By Deflection command, the command line and tooltips prompt you to define a direction to deflect the angle off of by selecting or clicking two points; then you’re prompted for a deflection angle followed by a distance.
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| The tooltip for the Create Line By Deflection command |
Create Line By Station/Offset Command
To use the Create Line By Station/Offset command, you must have a Civil 3D Alignment object in your drawing. The line created from this command allows you to start and end a line on the basis of a station and offset from an alignment.
You’re prompted to choose the alignment and then input a station and offset value. The line
begins at the station and offset value. You will not see a line form until at least two points are specified.
When prompted for the station, you’re given a tooltip that tracks your position along the alignment. You can graphically choose a station location by clicking it in the drawing. Alternatively, you can enter a station value on the command line.
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| The Create Line By Station/Offset command provides a tooltip for you to track stationing along the alignment |
Once you’ve selected the station, you’re given a tooltip that is locked on that particular station and tracks your offset from the alignment. You can graphically choose an offset by clicking the station in the drawing, or you can type an offset value on the command line. A negative value for offset indicates an offset on the left side of the alignment.
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| The Create Line By Station/Offset command provides a tooltip that helps you track the offset from the alignment |
Create Line By Side Shot Command
The Create Line By Side Shot command starts by asking you to select a line (or two points) that will be the backsight for creating a new line and subsequent lines while in the command. After you select the first line, you will see a yellow glyph indicating your occupied point. By default, Civil 3D is looking for an angle-right and distance to establish the first point of the new line. However, you can follow the command prompts to change the angle entry to bearing, deflection, or azimuth, if needed. You can also use the command-line options to change to counterclockwise.
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| The tooltip for the Create Line By Side Shot command tracks the angle, bearing, deflection, or azimuth of the side shot |
Create Line By Extension Command
The Create Line By Extension command is similar to the AutoCAD Lengthen command. This command allows you to add length to a line or specify a desired total length of the line.
Figure A shows the summary report that will pop up indicating the changes made to the line.
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| Figure A: The Create Line By Extension command provides a summary of the changes to the line |
The advantage of the Create Line By Extension command over simply using the Lengthen command is the summary report that appears at the command line. The summary report shown in
Figure B shows the same beginning coordinate as in
Figure A but a different end coordinate, resulting in a total length of 100’ (30.5 m).
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| Figure B: The summary report on a line where the command specified a total distance |
Create Line From End Of Object Command
The Create Line From End Of Object command lets you draw a line tangent to the end of a line or arc (but not polyline) of your choosing.
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| The Create Line From End Of Object command lets you add a tangent line to the end of an arc |
Create Line Tangent From Point Command
The Create Line Tangent From Point command is similar to the Create Line From End Of Object command, but Create Line Tangent From Point allows you to choose a point of tangency that isn’t the endpoint of the line or arc. Use the Nearest or Midpoint Osnap to pick a point on the line. If you pick an endpoint, the command behaves the same as Create Line From End Of Object.
Create Line Perpendicular From Point Command
Using the Create Line Perpendicular From Point command, you can specify that you’d like a line drawn perpendicular to any point of your choosing along a line or arc. In the example shown in the
Figure below, a line is drawn perpendicular to the endpoint of the arc.
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| A perpendicular line is drawn from the endpoint of an arc using the Create Line Perpendicular From Point command |
