Editing Feature-Line Geometry

Feature-line revisions often require adding PIs, breaking apart feature lines, trimming, and performing other horizontal operations without destroying the vertical information. To access the commands for editing feature-line horizontal information, select the feature line to access the Feature Line contextual tab and toggle on the Edit Geometry panel, as shown in Figure 14.11.

The first two tools are designed to manipulate the PI points that make up a feature line:

1. Insert PI The Insert PI tool allows you to insert a new PI, controlling both the horizontal and vertical design.
   
2. Delete PI The Delete PI tool removes a PI. If the PI is located at the beginning or end of a feature line, the beginning or end segment is removed. If the PI is removed at a PC, the arc is removed and the segment leading into the arc gets stretched to the next PI. If the PI is removed at a PT, the arc segment gets stretched to the next PI.
   

The next few tools act like their AutoCAD counterparts, but they are used specifically with feature lines because elevations are involved, and they will add PIs accordingly:

1. Break The Break tool allows two feature lines to be created from one. Additionally, if a feature line is part of a surface definition, both new feature lines are added to the surface definition to maintain integrity. Elevations at the new PIs are assigned on the basis of an interpolated elevation.
   
2. Trim The Trim tool operates much like the AutoCAD Trim command, trimming a feature line and adding a new end PI on the basis of an interpolated elevation.
   
3. Join The Join tool creates one feature line from two or more, making editing and control easier. You can set the tolerance distance from the settings associated with the Join tool on the Settings tab of Toolspace by doing the following:
   
   1. Expand the Grading Commands branch.
   2. Right-click JoinFeatures and select Edit Command Settings.
   3. In the Edit Command Settings – JoinFeatures dialog, expand the Feature Line Join property to change the tolerance.
4. Reverse The Reverse tool changes the direction of a feature line and flips any labels applied to the feature line on the opposite side.
   
5. Edit Curve The Edit Curve tool allows you to modify or delete the radius that has been applied to a Feature Line object. Once the feature line is selected, the Edit Feature Line Curve dialog will display. For each curve, you can modify the radius while viewing information on the curve length, chord length, and tangent length. There is also an option to maintain tangency if the curve is not already tangent to attached linework. After entering a value for the radius, a preview of the resulting curve will appear. Values that won't compute will not be accepted. In that case, a warning message will appear. There is also an option to pick two points to define a radius length. You can click the Apply button to continue making edits to other curves of the feature line or click the OK button to complete the command and dismiss the dialog.
   
6. Fillet The Fillet tool inserts a curve at PIs along a feature line and will join feature lines sharing a common PI that are not actually connected. You can apply a radius to a single PI or to all PIs on a feature line.
   

The last few tools refine feature lines, making them easier to manipulate and use in a surface:

1. Fit Curve The Fit Curve tool analyzes a number of elevation points and attempts to define a working arc through them all. This tool is often used when the corridor utilities are used to generate feature lines. These derived feature lines can have a large number of unnecessary PIs in curved areas. You can modify the tolerance and the minimum number of segments by entering O to select Options on the command line during the prompt to display the Fit Curve Options dialog.
   

   Alternatively, you can set the default values for these options from the settings associated with the Fit Curve tool on the Settings tab of Toolspace by doing the following:

   1. Expand the Grading Commands branch.
   2. Right-click FitCurveFeature and select Edit Command Settings.
   3. In the Edit Command Settings – FitCurveFeature dialog, expand the Feature Line Fit Curve property to change the tolerance and specify the minimum number of segments.
2. Smooth The Smooth tool takes a series of disjointed feature-line segments and creates a best-fit curve. This tool is great for creating streamlines or other natural terrain features that are known to curve, but there's often not enough data to fully draw them that way. You can also straighten previously smoothed feature lines on the Modify tab Edit Geometry panel by choosing the Smooth command and typing S for Straighten. Notice that the Smooth command accessed through the Feature Line contextual tab does not give you the Straighten option.
   
3. Weed The Weed tool allows the user to remove elevation points and PIs on the basis of various criteria. Once you select the feature line or multiple feature lines or a partial feature line, the Weed Vertices dialog will display. This dialog will allow you to weed based on any combination of angle, grade, or length; in addition, you can remove points based on their 3D distance between one another.
   
   • Weeding by angle considers the horizontal angles at each bend of the feature line and will delete a vertex smaller than the value entered.
   • Weeding by grade looks at three points, considering the middle point as a PVI. If the difference in grade is less than the entered amount, the PVI will be deleted.
   • Weeding by length looks at three points and will delete the middle point if the distance between the outside points is less than the value entered.
   • Weeding by 3D distance looks at the slope distance between two adjacent points and will delete the following vertex if the slope distance is less than the value entered.

   At the bottom of the Weed Vertices dialog, it states how many of the total number of vertices will be weeded. This is great for cleaning up corridor-generated feature lines as well.

   Similar to the Join and Fit Curve tools, you can set the default settings associated with the Weed command on the Settings tab of Toolspace by doing the following:

   1. Expand the Grading Commands branch.
   2. Right-click WeedFeatures and select Edit Command Settings.
   3. In the Edit Command Settings – WeedFeatures dialog, expand the Feature Line Weed property to change the various default values.
4. Stepped Offset The Stepped Offset tool allows offsetting in a horizontal and vertical direction, making it easy to create stepped features such as stairs or curbs.
   

In this exercise, you'll manipulate some feature lines that were roughed in to define the pool area at the recreational center:

1. Open the 1402_FeatureLineGeometry.dwg or 1402_FeatureLineGeometry_METRIC.dwg file.
2. Zoom into the area where the sidewalk intersects the edge of the concrete at the southwest edge of the building, and select the edge of the concrete, as shown in Figure 14.12.

   

3. If the Edit Geometry panel isn't visible, from the Feature Line contextual tab Modify panel, choose Edit Geometry to toggle on the Edit Geometry panel.
   
4. From the Feature Line contextual tab Edit Geometry panel, choose the Break tool.
   
5. At the Select an object to break: prompt, select the edge of concrete feature line again.
6. At the Specify second break point or [First point]: prompt, enter F ↲ to pick the first point of the break.
7. At the Specify first break point: prompt, using a Node Osnap, select the node of point #5, as shown in Figure 14.13.

   

8. At the Specify second break point: prompt, using a Node Osnap, select the node of point #6, leaving a gap, as shown in Figure 14.14.

   

   The feature lines representing the sidewalk and the edge of concrete at the pool area were roughed in and are not joined. Feature lines that represent continuous line work are much easier to manage when they are joined.

9. With the small segment drawn from point #6 to the edge of the building still selected, from the contextual tab Edit Geometry panel, click Join.
   
10. At the Select the connecting feature line, polyline or 3D polyline or [Multiple]: prompt, select all the magenta feature lines representing the sidewalk and the edge of concrete, as shown in Figure 14.15.

    

11. Press ↲ to end the command.
12. Press Esc to deselect.

    If you zoom out slightly, you may notice the green feature line representing the edge of pavement that is wrapping around the back of the building. It needs to connect up with the magenta feature line you just joined. Although there is a special Trim command that you must use with feature lines, the AutoCAD Extend command is the tool to use when you need to lengthen feature lines to meet others.

13. Execute the AutoCAD Extend command (you can type Ex ↲ at the command line).
14. At the Select boundary edges … Select objects or <select all>: prompt, select the magenta feature line as the boundary edge.
15. Press ↲ to advance to the next prompt.
16. At the Select object to extend or shift-select to trim or [Fence Crossing Project Edge Undo]: prompt, select the green feature line to the rear of the building close to the end of the segment that must be extended.
17. Press Esc to end the command.

    The edge of pavement feature line should be extended to the joined feature line, as shown in Figure 14.16.

    

18. Select the magenta feature line.
19. From the contextual tab Edit Geometry panel, click the Trim tool.
    
20. At the Select cutting edges: prompt, select the green feature line that was just extended.
21. Press ↲ to advance to the next prompt.
22. At the Select objects to trim: prompt, select the end of the joined feature line that extends south of the green one.
23. Press Enter to end the command.

    Next you'll join the magenta feature line to the green one. Similar to the AutoCAD Join command, the entity selected first will pass its properties onto those selected after.

24. Select the magenta feature line if not already selected.
25. From the contextual tab Edit Geometry panel, click the Join tool.
    
26. At the Select the connecting feature line, polyline or 3D polyline or [Multiple]: prompt, select the green feature line.
27. Press ↲ to end the command.
28. Press Esc to deselect.

    At this point in the exercise, your drawing should look like Figure 14.17 containing one feature line representing the edges of the sidewalk joining the edge of concrete around the pool area.

    

    Next, you will round one of the corners of the pool area to accommodate landscape.

29. Select the magenta feature line.
30. From the contextual tab Edit Geometry panel, click the Fillet tool.
    
31. Hover the cursor over the southwest corner of the magenta feature line, as shown in Figure 14.18.

    

    As you hover near the corner, you will see a preview of the fillet with the current radius value following the cursor. Just as with the AutoCAD Fillet command, you could use the options at the command prompt to change the radius value.

32. Click near the corner to place the fillet using the default radius value.
33. Press Esc twice to end the command and deselect.

    To adjust the radius value of the curve, do the following:

34. Select the magenta feature line.
35. From the contextual tab Edit Geometry panel, click the Edit Curve tool.
    
36. At the Select feature line curve to edit or [Delete]: prompt, select the magenta feature line on the curve.
37. In the Edit Feature Line Curve dialog, type 24' (8 m) for a new radius value. If you press Tab after entering the radius value, then you can see a preview of the curve before clicking OK.
38. Click OK to close the dialog.
39. Press Esc to end the command.
40. With the feature line still selected, notice the PI labeled extra PI next to the parking lot.

    Sometimes when you piece together your linework, you can end up with extra vertices. Before proceeding to applying elevations to your PIs, you should delete any extras you don't need.

41. From the contextual tab Edit Geometry panel, click the Delete PI tool.
    

    You will see triangular glyphs appear at each vertex of the feature line. When your cursor nears a vertex, the glyph turns green indicating that it will be deleted if you click now.

42. At the Specify Point: prompt, hover your cursor over the extra PI and left-click.
43. Press Esc three times to end the command and deselect.

    Your site should now look like Figure 14.19.

When this exercise is complete, you can close the drawing. A saved copy of this drawing (1402_FeatureLineGeometry_FINISHED.dwg or 1402_FeatureLineGeometry_METRIC_FINISHED.dwg) is available from the book's web page.

Editing Feature Line Elevations

To access the commands to edit feature line elevation, from the Feature Line contextual tab Modify panel, choose the Edit Elevations toggle to open the Edit Elevations panel.

The first tool in this panel is the Elevation Editor, which will activate a palette in Panorama where you can inspect station, elevation, length, and grade information about the feature line selected in a tabular grid format. You can edit elevation and grade in this interface. When you are working in a row in the Elevation Editor, the corresponding point will be shown with a temporary triangular glyph on the plan.

A number of tools are available for modifying and manipulating feature-line elevations. You will be using a few of them in the upcoming exercises. In this first exercise, you'll take a brief look at the Grading Elevation Editor tools:

1. Open the 1403_EditingFeatureLineElevations.dwg or 1403_EditingFeatureLineElevations_METRIC.dwg file.
2. Select the red feature line representing the tennis court area to activate the Feature Line contextual tab.
3. On the Feature Line contextual tab Edit Elevations panel, choose the Elevation Editor tool. Then press Esc to deselect the feature so you can observe feature line glyphs while working in the Grading Elevation Editor.

   The Grading Elevation Editor in Panorama will open, as shown in Figure 14.20.

   

   A series of symbols appears in the far-left column of the Grading Elevation Editor; these are the same glyph symbols used on the feature line grips. A triangular symbol denotes a PI, and a circular symbol denotes an elevation point. In this example, you don't have any elevation points.

4. Click in the Station column for the first PI at Station 0+00.00 (or 0+000.00).

   As a row is selected in the Grading Elevation Editor, the PI or the elevation point that was selected will be highlighted on the graphic with a small glyph.

   You can use the Grading Elevation Editor to make changes to the Station, Elevation, Length, Grade Ahead, and Grade Back settings. The exception is that you cannot edit stationing or length for PI points, as indicated by triangle glyphs in the Grading Elevation Editor.

   Across the top of the Grading Elevation Editor are multiple tools that will be used as you edit the data in the table:

   1. Select Clicking the Select tool allows you to select the feature line on the screen for editing in the Grading Elevation Editor. You can also select a parcel or survey figure.
      
   2. Zoom To The Zoom To tool will do exactly as it says. If a station is highlighted in the Panorama and you select the Zoom To tool, your plan view will be zoomed to that station on the feature line on the screen. When multiple stations are selected, the Zoom To tool will fit those multiple stations into your drawing window.
      
   3. Quick Profile The Quick Profile tool will generate a temporary profile based on the feature line selected. This is the same tool discussed earlier that was available on the Feature Line contextual tab Launch Pad panel. The Create Quick Profiles dialog will open, allowing you to select which surfaces you want to display, as well as what profile view style and 3D entity profile you want.
      
   4. Raise/Lower Clicking the Raise/Lower tool will activate the Set Increment text box. This will allow you to raise or lower selected station points by the value entered in the text box. If no station points are selected, it will raise or lower the entire feature line to the elevation displayed in the text box. This is an actual elevation, not an elevation difference, and you must press the Enter key to apply the elevation.
      
   5. Raise Incrementally and Lower Incrementally The Raise Incrementally/Lower Incrementally tools will raise or lower the station point or points by the amount listed in the Set Increment text box. This is an elevation difference.
      
   6. Set Increment The Set Increment tool activates the text box used with the Raise Incrementally and Lower Incrementally tools. This text box must be activated and supplied a value before proceeding with these tools. Negative values are not accepted in the Set Increment text box.
      
   7. Flatten Grade Or Elevations The Flatten Grade Or Elevations tool enables you to assign either one elevation to selected station points or a constant slope between selected station points. If you want to flatten the elevations, the elevation of the first selected station point will be applied to the other selected points. If nothing is selected, the elevation of the first point on the list will be used. If you want to apply a constant grade across a selected group of station points, the elevation of the first and last points in the selection will be held, and all points in between will be flattened to the grade calculated between the first and last points. When this tool is selected, the Flatten dialog will open asking if you want to flatten by constant elevation or by constant grade.
      
   8. Insert Elevation Point The Insert Elevation Point tool will let you select a spot on the feature line and will create an elevation point. The Insert PVI dialog will open, allowing you to fine-tune the station and elevation values.
      
   9. Delete Elevation Point The Delete Elevation Point will delete a point or points that are highlighted in the Grading Elevations Editor. Note that this tool will allow you to delete only elevation points.
      
   10. Elevations From Surface Clicking the Elevations From Surface tool will open the Select Surface dialog if there are multiple surfaces from which to choose. If you have selected a station point or points, it will assign elevations to only those points. If no station points are selected, the entire feature line will be draped over the surface, assigning elevations to all station points.
       
   11. Reverse The Direction The Reverse The Direction tool will do exactly as it says; it will reverse the direction of the feature line, thereby changing the direction of the stationing and the grade-ahead/grade-back directions.
       
   12. Show Grade Breaks Only The Show Grade Breaks Only tool is a toggle (click, it's on, and click, it's off) that will display only the rows where the grade breaks on the feature line. Therefore, if two adjacent segments share the same grade value, the station point that they share will be hidden because the grade doesn't break on that point.
       
   13. Unselect All Rows The Unselect All Rows tool does exactly as it says; it will deselect any rows that have been highlighted for editing.
       
5. Click the green check mark in the upper-right corner to dismiss Panorama.

Using the Grading Elevation Editor is the most basic way to manipulate elevation information. Keep this drawing open for use in the next exercise.

Using Other Feature-Line Elevation Editing Tools

To access the commands for editing feature-line elevation information, select a feature line to access the Feature Line contextual tab and toggle on the Edit Elevations panel, as shown in Figure 14.21. Many of the tools in the Elevation Editor may seem redundant from the Grading Elevation Editor tools discussed earlier, but they are placed here for ease of use.

Moving across the panel beyond the Elevation Editor tool, which was just discussed, you find the following tools for modifying or assigning elevations to feature lines:

1. Insert Elevation Point The Insert Elevation Point tool inserts an elevation point at the point selected or multiple elevation points at a specified increment. The elevation occurring on the feature line at the location inserted will be assigned to the elevation point. This elevation can be edited later. Note that elevation points can control only elevation information; an elevation point cannot be moved to alter the original orientation of the feature line.
   
2. Delete Elevation Point The Delete Elevation Point tool deletes the selected elevation point; the points on either side then become connected linearly on the basis of their current elevations. You can also delete all elevation points on a feature line with this command. When deleting an elevation point, the one that will be deleted is highlighted in green.
   
3. Quick Elevation Edit The Quick Elevation Edit tool allows you to use onscreen cues to set elevations and slopes quickly between PIs on any feature lines.
   
   • Hover over a PI or an elevation point and a triangular glyph appears showing the elevation of that station point at the cursor. Click to trigger the prompt at the command line and type in a new elevation.
   • Hover over a segment on the feature line and an arrowhead glyph appears showing the direction and grade of the segment. Click to trigger the prompt at the command line and type in a new grade. The elevation of the PI in which the arrow is pointing to will adjust.
4. Edit Elevations The Edit Elevations tool steps through the selected feature line, much like working through a polyline edit at the command line, allowing you to change elevations and grades or insert, move, and delete elevation points. A triangular glyph shows up at the current vertex. To skip editing the vertex and move on to the next, press the Enter key to accept the current value.
   
5. Set Grade/Slope Between Points The Set Grade/Slope Between Points tool sets a continuous slope along the feature line between selected points. As you select the points, you will be asked to specify or verify the elevation at each point.
   
6. Insert High/Low Elevation Point The Insert High/Low Elevation Point tool places a new elevation point on the basis of two picked points: the grade ahead of the first point and the grade behind the second point. This calculated point is placed at the intersection of two vertical slopes.
   
7. Raise/Lower By Reference The Raise/Lower By Reference tool allows you to adjust a feature-line station point vertically based on a grade, slope, or elevation difference in relation to a point on another 3D object or point. This relationship isn't dynamic!
   
8. Set Elevation By Reference The Set Elevation By Reference tool at first looks like the same command as the Raise/Lower By Reference tool. The differences are that you can execute this tool on multiple points on the feature line without leaving the command, and you can insert new elevation points. This relationship isn't dynamic!
   
9. Adjacent Elevations By Reference The Adjacent Elevations By Reference tool allows you to adjust the elevation of multiple vertices on a feature line by specifying grade, slope, or elevation difference from another 3D object. If the 3D object has length, elevations are projected to the feature-line station points perpendicularly from the 3D object. This relationship isn't dynamic!
   
10. Grade Extension By Reference The Grade Extension By Reference tool allows you to set the grade, slope, or elevation difference between feature-line segments across a gap. For example, you might use this tool along the back of curbs at locations such as driveways or intersections. This relationship isn't dynamic!
    
11. Elevations From Surface The Elevations From Surface tool sets the elevation at each PI and elevation point on the basis of the selected surface. It will optionally add elevation points at any point where the feature line crosses a surface TIN line.
    
12. Raise/Lower The Raise/Lower tool simply moves the entire feature line in the z direction by an amount entered at the command line. A positive number raises and a negative number lowers.
    

Some of the tools can be difficult to understand, so you'll look at them in the next exercise and see how they function in some basic scenarios:

1. If not opened for the previous exercise, open the 1403_EditingFeatureLineElevations.dwg or 1403_EditingFeatureLineElevations_METRIC.dwg file. You do not need to have completed the previous exercise to proceed.
2. Zoom into the entrance to the parking lot of the site.

   Notice that the corridor has been cleaned up at the entrance. A region was inserted and an assembly was used that omitted the curb, gutter, and sidewalk in the entrance area. To review regions and the use of multiple assemblies in a corridor, see Chapter 10, “Advanced Corridors, Intersections, and Roundabouts.”

   Also, two feature lines were extracted from the corridor representing the flowline at the curb and gutter on both sides of the region. They are dynamically linked to the corridor so they will update if the corridor is modified. To review the Feature Lines From Corridor command, see Chapter 9.

3. On the Prospector tab, expand the Sites Parking Lot collection.
4. Right-click Feature Lines and select Properties from the context menu.
5. In the Feature Line Site Properties dialog on the Options tab, do the following:
   1. Fill in the Filter Unused Styles check box.

      Only the styles in use will display.

   2. Highlight the Corridor Grading style.
   3. Click the up arrow button a number of times to move the Corridor Grading feature line style to the top of the list, as shown in Figure 14.22.
      

      

      This will set the initial priority by style when feature lines cross where no PIs exist. This means that the feature line style that is higher on the list will set the elevation where it intersects another. If the feature lines have the same style applied, the one modified last will win.

   4. Click OK to close the dialog.
6. Select the white polyline representing the edge of pavement of the parking lot.
7. On the Home tab Create Design panel Feature Line drop-down, select Create Feature Lines From Objects.
8. In the Create Feature Lines dialog, do the following:
   1. Set the Site to Parking Lot.
   2. In the Style area, use the drop-down to set the Style to Grading Edge Of Pavement.
   3. Under Conversion Options, clear the check box for Assign Elevations And Weed Points. The Erase Existing Entities check box should remain checked.
   4. Click OK to close.
9. Select the newly created feature line.
10. On the contextual tab Edit Elevations panel, select the Elevation Editor tool.
11. Scroll through the Grading Elevation Editor to review it.

    Notice that the elevations of the feature line at stations 0+00 and 9+21.75 (0+000 and 0+280.97 if metric) are already set because these stations were touching the extracted corridor feature lines when the polyline was converted. The feature line is matching grade with the road at the flowline on both sides of the entrance.

12. Leave the Grading Elevation Editor open. Either push it to the side or minimize it.
13. With the feature line still selected, on the contextual ribbon Edit Elevations panel, click Quick Elevation Edit.
    
    1. Hover over the middle of the left curb return. Use your scroll button to zoom in or out if necessary.

       Notice the triangular glyph that appears on the segment, which changes directions depending on which end of the segment your cursor is nearest. The direction in which the triangle is pointing is the direction in which you will be applying the grade. Notice that the triangular glyph turns gray when it points to where the edge of pavement feature line touches the corridor's dynamically linked feature line. This glyph indicates that this elevation is being influenced by another feature line.

    2. Position the cursor so that the triangular glyph is pointing toward the parking lot, as shown in Figure 14.23, and left-click.

       

    3. At the Specify grade or [Slope]: prompt, type 3 ↲ to specify a 3 percent grade.
    4. Go to the Grading Elevation Editor and scroll to the bottom of the list to look at the elevation assigned at station 8+90.59 (0+271.46 if metric).
    5. With the Quick Elevation Edit tool still running, hover over the PT of the right curb return of the entrance.

       A tooltip showing elevation will appear with an equilateral triangular glyph, as shown in Figure 14.24. With the Quick Elevation Edit tool, not only can you edit the grade or slope of a feature line segment, but you can also edit the elevation of a PI.

       

    6. Click over the PI.
    7. At the Specify elevation or [Surface]: prompt, type 7.07 (2.151 if metric).
    8. Check the Grading Elevation Editor at station 0+31.70 (0+009.67 if metric), and notice that the elevation you just typed in has been assigned to the second station on the list.
    9. Leave the Grading Elevation Editor open.
    10. Press Esc twice to end the command and deselect.
14. Pan over to the Building feature line and select.

    Previously, you used the Elevations From Surface tool to assign elevations to the feature line. You also had the Insert Intermediate Grade Break Points check box filled. Figure 14.25 displays how the Set Elevations From Surface dialog was configured in the previous exercise.

    

    The circular grips called elevation points on the feature line are there because TIN lines from the surface crossed the feature lines at those locations. You will remove the elevation points from the feature line so you can set elevations at just the four corners of the building for now.

15. With the feature line still selected, on the contextual tab Edit Elevation panel, select Delete Elevation Point.

    As the cursor nears the feature line, circular glyphs appear where the circular grips are located, and triangular glyphs appear at the four corners. This tool will remove only the circular glyphs (elevation points).

    1. At the Specify point or [All]: prompt, type A ↲.
    2. Press Esc to end the command.

    If you take a look at the Grading Elevation Editor on Panorama, you may notice that it is still displaying the numerous stations associated with the parking lot feature line. The Grading Elevation Editor will not automatically change its contents based on the current selection.

16. In the Grading Elevation Editor tab on Panorama, do the following:
    1. Click the Select A Feature Line, Parcel Line, or Survey Figure tool, which is the green button in the upper-left corner of Panorama.
       

       Since the feature line was still selected when you clicked the tool, the Grading Elevation Editor instantly updated.

    2. Select all the PIs by selecting the first line, then holding the Shift key down, and selecting the last line.
    3. Click into one of the elevation fields and enter 8 (2.5 for metric) to set the initial elevation of each PI outside the building.
17. In the Grading Elevation Editor tab on Panorama, click the Select A Feature Line, Parcel Line, or Survey Figure tool.
18. Using the pick box, select the magenta feature line representing the edge of the concrete around the pool area.

    Notice that an elevation has been assigned to the beginning station of the feature line at point 1. Since the edge of concrete feature line intersects the building feature line, they are sharing the same elevation. The final station near the northeast corner of the building at point 8 should be set by the building feature line, but it is still at elevation 0. Zooming in closer to this area will reveal that the feature line doesn't quite intersect the building. Since you need the PI of the building and the PI of the edge of concrete to match elevations at this location, you will connect them.

19. Click the magenta feature line, click the grip of the PI near point 8, and Endpoint Osnap it to the northeast building corner.

    The Grading Elevation Editor will update, as shown in Figure 14.26. Notice the + sign near the bottom-right corner of the green triangle in the first and last rows? That shows that the feature lines touch.

    

20. Close Panorama by clicking the green check mark in the upper-right corner.

    Next, you'll set the grades on the edge of concrete feature line. The object is to get the runoff to flow away from the building toward the southern end of the site.

21. Select the magenta feature line, and on the contextual ribbon Edit Elevation tab, select Set Elevation By Reference.
    
    1. At the Specify the reference point: prompt, Endpoint Osnap to the northeast corner of the building at point 8.
    2. At the Specify point or [Insert]: prompt, hover over the northeast corner of the edge of concrete near point 7 and left-click (there is no need to use Osnaps), as shown in Figure 14.27.

       

    3. At the Specify grade or [Slope Difference]: prompt, type −0.5 ↲ for grade.

    The command will repeat itself so you can select another point to be graded relative to the reference point selected when the command launched.

22. On the contextual ribbon Edit Elevation tab, select Set Elevation By Reference to reset the command.
    1. At the Specify reference point: prompt, Endpoint Osnap on the northeast corner of the edge of concrete at point 7 (the point you just assigned an elevation to).
    2. At the Specify point or [Insert]: prompt, click the southeast corner of the edge of concrete at point 6.
    3. At the Specify grade or [Slope Difference]: prompt, type −0.5 ↲ for grade.
23. On the contextual ribbon Edit Elevation tab, select Set Elevation By Reference to reset the command.
    1. At the Specify reference point: prompt, Endpoint Osnap on the first PI of the magenta feature line at point 1 on the south side of the building, as shown in Figure 14.28.

       

    2. At the Specify point or [Insert]: prompt, click the next PI on the magenta feature line at point 2.
    3. At the Specify grade or [Slope Difference]: prompt, type −1 ↲ for grade.
    4. At the Specify point or [Insert]: prompt, click the PI on the magenta feature line at point 3.
    5. At the Specify grade or [Slope Difference]: prompt, type −1 ↲ for grade.
    6. At the Specify point or [Insert]: prompt, click the PC on the magenta feature line at point 4.
    7. At the Specify grade or [Slope Difference]: prompt, type −1 ↲ for grade.
    8. Press Esc to end the command.
24. On the contextual ribbon Edit Elevation tab, select Elevation Editor.

    In the Grading Elevation Editor, note that stations 0+48.81 through 2+76.75 (0+015.48 through 0+084.96 if metric) are still at elevation 0. These PIs occur in the sidewalk area and you'll grade them later. Station 4+20.80 (0+129.26 if metric) occurs at the PT at point 5. You'll apply a continuous grade between points 4 and 6.

    1. Select stations 3+83.10 through 5+74.16 (0+116.69 through 0+175.32 if metric) in the Grading Elevation Editor.
    2. Select the Flatten Grade Or Elevations tool at the top of the Grading Elevation Editor.
       
    3. In the Flatten dialog, select Constant Grade and click OK to assign.

       According to the Grading Elevation Editor, a grade of −0.43 has been assigned. Now you'll set a low point at the midpoint of the segment between points 5 and 6.

    4. Close the Grading Elevation Editor. The magenta feature line should still be selected.
25. On the contextual ribbon Edit Elevation tab, select Insert High/Low Elevation Point.
    
    1. At the Specify the start point: prompt, select the PI at point 6.
    2. At the Specify the end point: prompt, select the next PI at point 5.

       A triangular directional glyph appears near the last point picked, indicating the direction the grade will be applied.

    3. At the Specify grade ahead or [Slope]: prompt, type −1 ↲.

       A triangular directional glyph appears now near the first point picked indicating the direction the next grade will be applied.

    4. At the Specify grade back or [Slope]: prompt, type −0.5 ↲.

       The location of the low point is calculated with the grades provided, and a circular elevation point is inserted at that location, as shown in Figure 14.29.

       

    5. Press Esc twice to end the command and deselect.

    To set the grades on the sidewalk, you will get a little crafty. You'll create a temporary surface that defines a grade of 2 percent away from the building. Then you'll assign elevations to the sidewalk area with this surface. You will do something similar later in the next section using grading groups.

26. Select the building feature line and on the contextual ribbon Edit Geometry tab, select Stepped Offset.
    1. At the Specify offset distance or [Through Layer]: prompt, type 25 (8 if metric) ↲.
    2. At the Specify side to offset or [Multiple]: prompt, pick a point outside the building area.
    3. At the Specify elevation difference or [Grade Slope Elevation Variable]: prompt, type G ↲ to specify grade.
    4. At the Specify grade or [Slope Elevation Difference Variable]: prompt, type −2 ↲. Press Esc twice.
27. Select the new feature line, and on the contextual tab, expand the Modify panel to select Move To Site.
    1. In the Move To Site dialog under Destination Site, select Temp.
    2. Click OK to close.

    Leaving the new feature line in the same site as the edge of concrete and building feature line would have caused an elevation point to have been inserted wherever it crossed over these feature lines. Moving it to another site keeps that from occurring.

28. Select the building feature line and the new offset feature line.
29. On the contextual tab Modify panel, click the Add To Surface As Breakline tool.
    1. In the Select Surface dialog, click the plus sign button to create a new surface.
       
    2. In the Create Surface dialog, type Temp for the surface name.
    3. For Style, click into the Style value field. Then click the ellipsis button to open the Select Surface Style dialog.
    4. In the Select Surface Style dialog, select the style called Border Only and click OK to close.
    5. Click OK to close the Create Surface dialog.
    6. Click OK to close the Select Surface dialog, and the Add Breaklines dialog opens.
    7. Under Supplementing Factor, fill in the Distance check box.
    8. In the Distance field, type 25 (8 if metric).

       Creating surface points at this frequency will produce a set of uniform triangles across the sidewalk area, which makes for a more accurate surface.

    9. Click OK to close, and press Esc to deselect the feature lines.
30. Select the magenta feature line, and on the contextual tab Edit Elevations panel, click Elevation Editor.
    1. In the Grading Elevation Editor, select the four PIs with an elevation value of 0 by holding down the Shift key during the selection.
    2. At the top of the Grading Elevation Editor, click the Elevations From Surface tool.
    3. In the Select Surface dialog, select the Temp surface using the drop-down and click OK.
    4. Click the green check mark in the Grading Elevation Editor to close it, and press Esc to deselect the feature line.

    Last, you will make an adjustment to the red feature line on the west side of the site representing the tennis court. As you may recall, the northwest corner was set by acquiring its elevation from the existing surface, and then from that corner typical cross slopes were applied. You will now raise the tennis court to ensure that it will be higher than the surrounding ground.

31. Select the red feature line representing the tennis court, and on the contextual tab Edit Elevations panel, click the Raise/Lower tool.
    1. At the Specify Elevation Difference: prompt, type 0.5 (0.15 for metric) ↲.
    2. Press Esc to deselect.

When this exercise is complete, you can close the drawing. A saved copy of this drawing (1403_Editing FeatureLineElevations_FINISHED.dwg or 1403_Editing FeatureLineElevations_METRIC_FINISHED.dwg) is available from the book's web page.

You are halfway to completing the construction of your grading model. In an upcoming section, you will use another grading tool called Grading Groups to assign elevations in the parking lot. By using all the tools in the Feature Lines toolbar, you can quickly grade elements of your design and pull them together in a surface.