Download Wiley Mastering AutoCAD Civil 3D 2012
Transcript
22 | Chapter 1 The Basics of AutoCAD Civil 3D Figure 1.19 The tooltip for the Create Line by Azimuth command Create Line By Angle Command The Create Line By Angle command prompts you for a turned angle and then a distance (Figure 1.20). This command is useful when you’re creating linework from angles right (in lieu of angles left) and distances recorded in a traditional handwritten field book (required by law in many states). Figure 1.20 The tooltip for the Create Line By Angle command Create Line By Deflection Command By definition, a deflection angle is the angle turned from the extension of a line from the backsight extending through an instrument. Although this isn’t the most frequently used surveying tool in this day of data collectors and GPSs, on some occasions you may need to create this type of line. When you use the Create Line By Deflection command, the command line and tooltips prompt you for a deflection angle followed by a distance (Figure 1.21). In some cases, deflection angles are recorded in the field in lieu of right angles. Figure 1.21 The tooltips 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/or 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. On the basis of the tooltips, you might expect the line to be drawn from the alignment station at offset zero and out to the alignment station at the input offset. This isn’t the case.