The command to draw a feature line has options to specify the levels of the feature line, including an option to retrieve the levels from a surface.
Click Home tabCreate Design panelFeature Line drop-downCreate Feature LineFind.
In the Create Feature Lines dialog box, specify an optional site, an optional name and an optional style for the feature line. Select a layer and note that the option to use a selected element layer is disabled. Click OK.
Select the start point for the line. You can use Osnaps or transparent commands to snap to existing geometry.
Specify the level for the start point by doing one of the following:
Enter a level at the command line.
Enter Surface (S)
to display the Select Surface dialog box and then do the following:
Select a surface from which to obtain the levels.
Select the Relative Level to Surface check box if you want the feature line to be relative to the surface. For more information, see About Relative Feature Lines.
Optionally enter a positive or negative offset value in the edit box. Click OK. You can later change the offset value at each point you specify.
Note: If there are no surfaces in the drawing, the Surface option is not available.
The following prompt is displayed if you are creating the feature line relative to the surface so that you can specify the relative level for each point:
Specify relative level or [Gradient/SLope/Level/Difference/SUrface/Transition] <0.000>:
Otherwise, the following prompt is displayed:
Specify grade or [SLope/Level/Difference/SUrface/Transition] <0.000>:
If you wish to specify each level point as you create points, skip down to Step 9. To continue drawing points without establishing the level until the end:
Enter the Transition command option.
Create a new point. When Transition is selected, as each subsequent point is created the level prompt will default to Transition.
Transition or [SLope/Level/Difference/SUrface] <Transition>
Press Enter to continue drawing another point(s) without specifying the level.
After creating points, select and enter the desired keyword to specify the level, gradient, slope, or level difference. If you end the command while still in the Transition prompt, you will be prompted to specify an ending level.
Do one of the following to establish the level of the second point:
Enter Relativetosurface (R) and enter a different relative level. The relative level is applied to the level of the surface you specified.
Note:
When you are drawing a feature line relative to a surface, if the second point you selected is not on the surface you specified, a message is displayed at the command line when you attempt to enter a relative level value and you are given the option to select a different surface. If you do not select a different surface, by default this second point will use the same level that was assigned to the first point and it will be absolute. If you do select a different surface, the level of the point will be derived from that surface but it will be absolute.
Enter Gradient (G) and enter a gradient. The gradient is applied to the segment between the first and second points.
Enter Slope (SL) and enter a slope. The slope is applied to the segment between the first and second points.
Enter Level (E) and enter a level. The level is applied to the second point and the gradient of the segment between the points is calculated.
Enter Difference (D) and enter a level difference between the first and second points.
Enter Surface (SU) to view and accept the surface level at that point, or to specify a different surface.
Note: A feature line can be relative to only one surface and that surface must be defined when you select the first feature line point. If you specify a different surface at this prompt, the level of this point will be derived from that surface but it will be absolute.
Specify the next point on the feature line by doing one of the following:
Select the next point in the drawing.
Enter Length (L) and enter a length. When you use this option, the direction of the segment is assumed to be the same as the end of the previous segment.
Specify the level of the point using the options described above.