Adjust Linestring Elevation Command

alan.sharp · June 4, 2020, 12:53pm

Adjust Linestring Elevation

Command Licensing and Default Menu Location

The Adjust Linestring Elevation command is part of the RPS Data Prep Toolbox
The command is located on the Data Prep macros menu ribbon
The command is located in the Modify menu group

Overview Video Demonstration

The Adjust Linestring Command has a number of elevate options, each option is covered in a separate use case video within the help section for that option / mode of use below. The following video is a quick overview of the command dialog and options available only.

Command Description

Provides a quick and easy way to elevate and adjust elevations in a variety of ways depending on the lines use case. Includes the ability to add varying elevations to lines as VPIs or 3D nodes, elevate contour sequences, elevate pads, elevate curb lines for parking lots to planar or 3D surfaces and to make elevation adjustments to sections of selected lines. Ideal for contours, pads, curb, gutter and sidewalk lines.

Latest Changes

April 24th 2024
The command has been reworked significantly to increase consistency between the modes of working as well as to add the Contour and Pad Modes of elevating lines. Hot Keys have been added for quick access to key functions.

November 30th 2023
Added elevate contour mode to rapidly elevate sequences of contours including new hotkeys to increment and decrement values, reverse direction, pop up method to reset elevation and sequence direction and more.

May 5th 2023
The command was updated to facilitate the following

In the Delta mode, when using a range for the elevation adjustment, the values of elevations displayed in the Start to Location mode for Start and Location 1 did not update correctly when you selected a second line after completing the first line. This has now been addressed.
In the Spot mode, depending on the source line selected for elevating, how it was created and if it had Extend Vertical enabled on adding the third elevation in 3D node mode a random elevation point was added to the end of the line. This has now been addressed.

October 3rd 2022
The command has been completely redesigned to accommodate the new Plane, Surface and Spot modes of adjusting elevations. The existing functionality has been maintained but the user interface has changed to facilitate the additions that have been made.

The new Plane mode allows you to elevate curved sections of linestrings to a 3 point plane, ideal for accurately elevating curb and gutter lines and parking islands that lie on an inclined plane. The method allows you to subdivide arcs into equal segments or to utilize arc to chord settings to subdivide arc elements for elevating purposes. This approach also adds uniformity to the model building process.

The new Surface Mode allows you to elevate curved sections of linestrings to a selected grading framework surface that defines the planar slopes of a parking lot. The method allows you to subdivide arcs into equal segments or to utilize arc to chord settings to subdivide arc elements for elevating purposes. This approach also adds uniformity to the model building process.

The new Plane and Surface modes, eliminate the issues typically associated with elevating curb and gutter using provided elevation call outs that will generate small sags or crests in curb elements due to the linear interpolation methods used to elevate lines between provided 3D points along the line.

The new Spot mode allows you to quickly and easily add elevations to 3D lines as either VPIs or as Horizontal nodes with elevation. You can click and enter elevation values or click and then click an elevation text or other 3D object to define the elevation for the clicked locations.

Command Interface Description

The Adjust Linestring Elevation command dialog looks as follows

The command provides the following modes of operation

Absolute - Set line or partial line elevations to an absolute elevation value +/- a secondary delta adjustment
Contour - Elevate sequences of contour lines that increment or decrement
Delta - Adjust line or partial line elevations by a delta or delta range over the selected range to taper lines into existing grades or elevations of existing features to match existing grade.
Pads - Elevate Pads, Create offset lines for subgrade, basement or overbuild using text or elevation values
Plane - Elevate lines or partial lines to a plane defined using 3 points. Ideal for curb returns and parking islands or bays.
Spot - Elevate lines using spot elevations created as either VPIs or 3D nodes on the line.
Surface - Elevate lines to a surface with specific controls over how and where to elevate lines through arc or curved sections.

Common Selection Requirements

In the Absolute, Delta, Plane and Surface Modes, the following setup options are common to each mode.

Portion

In Absolute, Delta, Plane and Surface modes you can select the line portion that you wish to elevate. This can be any of the following options

All - For single or multiple line selections, you can adjust the entire line or all lines selected
Start to Location - for single line selections, you can adjust the line from its start point to a defined location along the line.
Location 1 to Location 2 - for single line selections, you can adjust the line between two defined locations along the line.
Location to End - for single line selections, you can adjust the line from a defined location along the line to the end of the line.

When you select anything other than All, you will be asked to select the Location or Location 1 and 2 to define the range of the adjustment.

Primary Adjustment

In these modes you can make a primary adjustment and an optional secondary adjustment. The options for primary adjustment include the following

Constant
Range
Undefined (Only in absolute mode)

Constant Adjustment

In this mode you can set a single elevation that will be applied to the entire station range of the line selected. for example set the value to 100 if you want the line to be raised / lowered to that elevation over the range selected.

Range Adjustment

In this mode you can specify an absolute elevation to be applied at the start of the range and a second elevation value to be applied at the end of the range. The line will transition between those two elevations over the distance between those two points.

Undefined

In this mode you can eliminate all elevations that are defined on the line between the start and end point of the range selected. The elevation is computed at the start of the range and at the end of the range and locked in with new elevation controls, and all elevations between are removed. This mode only applies to the Absolute mode.

Secondary Adjustment

If you wish to further vary the elevations over the range, you can apply a secondary adjustment that is compounded with the primary adjustment to adjust the line elevations. For example you may wish to set the line elevation to 100 between the range points but then subgrade adjust that by a further 1’ to create the base of subgrade. The secondary adjustment can be

Constant
Range
None

An example of a secondary adjustment that is constant is a simple subgrade adjustment of 1’

An example of a secondary adjustment that is a Range Adjustment would be e.g. that at the start of the range the subgrade is 1’ thick but at the end of the range it is 1.5’ thick.

When you select the secondary adjustment mode, you will be asked to enter the value or values required when the mode is anything other than None.

Standard Hot Keys

While running the command, the following Hot Keys are always available. Each mode of the command may also have additional Hot Keys that are specific to the mode in use e.g. Contour or Pad Modes.

Hot Key	Description
Q	Rotate the plan view clockwise by 15 degrees
E	Rotate the plan view anti clockwise by 15 degrees
Shift Q	Rotate the plan view clockwise by 30 degrees
Shift E	Rotate the plan view anti clockwise by 30 degrees
CTRL ALT Q	Reset the rotation of the plan view to North Up
W	Pan the plan view South
A	Pan the plan view East
S	Pan the plan view North
D	Pan the plan view West

Absolute Mode

When the mode selected is Absolute, the command will allow for the following settings specific to the Absolute Mode

Hold Elevations checkboxes

When making an adjustment, you can elect to Hold the elevation at the beginning of the range and at the end of the range selected. for example if you are setting an absolute elevation of 90 to a line that is already at elevation 100, and you elect to hold the elevation at the start and or end of the range, the line will have an elevation of 100 at the start point, will drop vertically down to 90 and then stay at 90 to the end of the range and then jump back vertically to elevation 100.

If you do not hold the elevations at the start and or end of the range, then the line will taper from the point at which elevation was defined prior to the start of the range to the defined elevation at the start of the range, and the same in reverse at the end of the range.

Clear Linestring after applying changes checkbox

Check this checkbox if you want to clear the current line selection after each execution in readiness for a new line to be selected.

Command Execution Process

Select the Absolute Mode of operation
Select the Hold options and clear linestring options as required
Select the linestring(s) to be adjusted
Select the Portion of the line to be adjusted
Pick the locations to define the range as needed
Define the primary adjustment(s)
Define the secondary adjustments if required otherwise set to None
Click Apply to make the adjustments

Video Demonstration

Examples of Absolute Adjustments

Take this simple line as an example (no adjustments applied

If we now apply an absolute adjustment to the elevations between 2 locations with hold locking applied at the start and end of the adjustment range. We are using an elevation constant of 115’ using a Location 1 and Location 2 for the start and end point of the adjustment range. In this case there is no secondary adjustment.

If we undo that and then do it again and this time we remove the locks at the start and end point we will get this result

If we do the same thing again and this time we apply a secondary adjustment, the adjustment can be applied as None (no adjustment). Constant (a constant adjustment e.g. -2’ to remove a 2’ subgrade adjustment or Range where a value of adjustment is applied at the start and end of the adjustment range e.g. if you want a transitional subgrade adjustment you could add -2 at the start location and -4 at the end location to get a transition from -2 to -4 over the range of the linestring adjustment (this is what was applied below - you can see at the start point the elevation is 113 (115-2) and at the end it is 111 (115-4) and that there is a constant slope between the start and end points.

Contour Mode

This mode elevates a sequence of contour lines, starting with a specified value and increment / decrement delta value. Each line clicked increments or decrements the elevation value in readiness for the next contour line.

Video Demonstration

Notes

When you select Contour Mode, the View Filter Manager - Display Options - Display in an Alternate Color mode is automatically invoked, and the 2D lines that you will be elevating will be displayed in your RPS Settings - Secondary Highlight color e.g. Yellow. As the lines are selected and elevated they will change color back to the original color of the contour lines. This allows you to rapidly see which contours have been elevated vs which ones still need to be elevated.

We recommend that you use the RPS Isolate Layers command to select the layers of the contours that you want to elevate leaving the PDF image visible so that you can interpret the contour elevations while you work through each set of contours (Existing, Proposed etc.). This allows you to display both the index contours and the normal contours at the same time if they are on different layers.

The Contour Mode dialog looks as follows

Automatically adjust elevation checkbox

Check this checkbox to automatically increment or decrement the next contour elevation value by 1x the defined delta value after each contour is elevated.

When checked, select whether you want to Decrease or Increase the value by 1x the defined delta value after each contour is elevated.

Delta

Enter the contour interval that you are working with i.e. if the contours are 100, 101, 102 … then you have a delta of 1’, if the contours are 100, 102, 104, 106 … then you have a delta of 2’.

Elevation

Enter the starting elevation value for the first contour that you plan to elevate.

Note that the next contour elevation value is displayed on the cursor at all times so that you can tell what the next elevation will be when it is applied. This allows you to check your work as you execute the process.

Linestring

Select the linestring that you wish to elevate. Its elevation will be assigned and the dialog will prepare for the next contour to elevate. Simply click the contours in sequence. You will see that the elevation value that will be assigned to the next contour will be updated after each line is selected and will be displayed by the cursor in the graphics area. note that the value on the cursor will refresh as soon as you move the mouse.

Mode Specific Hot Key Controls

While running in this mode, the following Hot Keys are available to allow you to quickly make changes to the elevation or Decrease / Increase directions.

Hot Key	Description
Z	Decrease the next elevation by 1x delta
C	Increase the next elevation by 1x delta
SHIFT Z	Change the Increase / Decrease direction to Decrease and reduce the next Z value by 2x delta
SHIFT C	Change the increase / decrease direction to Increase and increase the next Z value by 2x delta
SHIFT X	Pop up a control by the cursor allowing you to manually define the next elevation value and optionally reset the increase / decrease direction

Note that when you use the Shift X Hot Key, the following elevation control dialog will pop up beside the cursor in the graphics window

Shift Z
Changes the direction of increment / decrement to Decrease. At the same time the contour elevation value is modified by 2x delta value i.e. if you were previously incrementing contour elevations and you had elevated 100, 101, 102, 103, 104 and 105 the cursor would now say 106 (if delta =1), you now reverse direction, the last contour elevated was 105 so the next contour if you are starting a decrementing sequence is likely to be 104 i.e. 2 x delta below the current cursor value (106).

Shift C
Changes the direction of increment / decrement to Increase. At the same time the contour elevation value is modified by 2x delta value i.e. if you were previously decrementing contour elevations and you had elevated 100, 99, 98, 97, 96 and 95 the cursor would now say 94 (if delta =1), you now reverse direction, the last contour elevated was 95 so the next contour if you are starting an incrementing sequence is likely to be 96 i.e. 2 x delta above the current cursor value (94).

Click on an already elevated line
If you click on a line that has already been elevated, the pop up dialog that allows you to reset elevation and increase / decrease direction will be displayed.

Delta Mode

This mode is similar to the Absolute mode in that it adjusts the elevation of a line or lines over the entire length of the lines (All) or over a specified range of the line (Portion) using the Start, End and or user defined Locations along the line, using a delta or range of delta elevation values. You can use the command to adjust lines to match grade at either the line end points or at points along the line e.g. where the lines have o match the elevation of an inlet, manhole, culvert etc.

Video Demonstration

The Delta Mode dialog looks as follows

Linestrings

Select the line or lines that you want to adjust. Note when you have the Portion All selected then you can select multiple lines, when you select one of the other portion options (a range) you can select only one line at a time.

Portion

The Portion allows you to select how you want to apply the Delta adjustments. The options available include

All - one or more entire lines
Start to Location - A single line from its start to a defined point on the line
Location 1 to Location 2 - A single line between two points on the line.
Location to End - A single line from a defined point on the line to its end point

Adjustment mode

The following options for delta adjustments are available

Constant - applies a single delta elevation adjustment to the line or portion of line selected
Range - Applies a variable delta elevation to the line using a value at the start of the portion, and a value at the end of the portion. For example if you want to match grade at the end of the line and want to taper the line elevations from a 0 adjustment 200’ from the end of the line to a -0.2’ adjustment at the end of the line.

Depending on the option selected you will be asked to enter either a Constant delta or the Delta at start and Delta at end values.

Pads Mode

The Pads mode allows you to elevate building pads or other fixed elevation lines using manually entered elevations, elevations extracted from clicked text labels, from 3D click locations, or from text that defines the elevations that is placed within the bounds of the building pad itself. You can also create offset lines if you need to subgrade adjust the pad, add an overbuild or compute a basement or footings adjustment etc.

Video Demonstration

The Pads mode dialog looks as follows

Pad mode

You can select from the following options to determine the method of deriving the Pad elevation

Elevation - enter an elevation or click on a piece of text or a 3D location to extract the elevation
From text - select the pad(s) and their associated elevation text values

Filter

When you select the From text pad mode, you can define a filter that can be used to find the correct value in a multi line text item that may contain one or more possible elevation values. In the absence of a Filter being applied, the first line of text will be used.

For example
Pad text that shows the following presents 3 possible values

Pad 001
FG=123.123
SG=122.123

If you do not define a filter then the elevation of this pad would be 1’
If you define a Filter FG then the elevation of the pad will be 123.123
If you define a Filter SG then the elevation of the pad will be 122.123
If a Filter is defined but no match is found, then the first line will be used and the elevation of the pad will be 1’

Pad elevation options

Create offset checkbox

Check the checkbox if you want to create an offset line to the source line with a different elevation. Note that if you use this option to model a subgrade adjustment or overbuild or basement footing, the line needs to be offset horizontally by e.g. 0.01 inside the pad line so that the model you later create does not have exactly vertical sides (slightly off vertical).

When checked enter the values required for the following settings

Direction

Select whether you want to offset the line Inside or outside the selected pad line (normally select inside).

Vertical Offset

Enter the value that you want to adjust the elevation of the offset line by i.e. if you are subgrade adjusting the pad by -2’ then enter -2’ here.

Horizontal Offset

Enter the value that you want to horizontally offset the pad line by i.e. if you are doing a -2’ subgrade adjustment or a 1’ overbuild then typically you will use an offset of e.g. 0.01’ so that any resulting model that includes the pad and offset lines does not have any perfectly vertical sides (surface model flags).

Name

Enter the name for the offset line you are creating e.g. Pad Subgrade or PAD SG etc.

Layer

Select or create a new layer for the offset line that you are creating.

Use elevation formula

If you have a large number of pads to elevate, and if you are entering the elevation values manually or if you are using text and the text is only defined to 2 digit coordinates e.g. on the plans it shows pad elevation as 46.56 but you know it is 4046.56 then you can use the elevation formula to minimize data entry or to correct values that are determined from text values on the drawing. An elevation formula of {Z}+4000 will convert 46.56 to 4046.56 etc. You can use standard math operators +, /, -, * to compute the desired values.

Auto Apply checkbox

When checked, the lines and or text that you select will be automatically computed without the need to click the Apply button. When unchecked you can make selections and then click the Apply button when you are ready to execute the elevation adjustments.

Linestring

Pick the linestring or linestrings that you want to adjust depending on the Pad mode option that you selected. When you select Elevation mode, you can select one line at a time and enter its elevation. When you select Text mode, you can select any number of pad lines plus any number of elevation text labels and it will compute all those that it can in a single step.

The command dialog will loop continuously using the same settings between select the line and enter the elevation value or select the lines and text / execute.

Plane Mode

The Plane mode will elevate curved and or straight sections of a selected linestring defined using a “Portion” range to a planar surface defined using 3 points.

Video Demonstration

The following video shows you how to use the Plane mode of adjustment

Video Demonstration

When modeling curb and gutter lines in 3D, you will often be provided with elevation spots at the PC and PT points of the curves. In some cases you may also be provided with elevations at mid curve or interval points around the curve also. In the latter cases, the curve sections will be elevated correctly when using the PC, PT and mid curve points, however where you are provided with the PC and PT points only, you will often find that the elevations along the curve will not create the surface as intended by the engineer.

This is because the curve was designed to fall on a grade plane and the elevations have been interpreted at the PC and PT points only on that grade plane, however when interpreted just from the PC and PT points around the curve (how TBC interpolates elevations of a line between provided vertical controls on a line by linear interpolation) you will find that you get a small sag or crest in the curve vs the intended planar grade for the curve.

Take the following example

The parking island was designed to lie on a plane defined by a rectangle where the south side is at elevation 100 and the North side is at elevation 101.50. The arcs are 4’ radius, and the elevations at the PC and PT points are all computed correctly. However when you look at the surface model generated using just this line where all the elevations are correct, clearly shows a warping of the plane at each of the arc corners (the non linear nature of the color bands across the island. This is caused by the fact that the elevation interpolation for the line is along the line between the PC and PT points rather in the N-S and E-W axes of the plane that was used to define the island.

In this exaggerated oblique view of the island you can see the problem more clearly

The Plane mode and Surface mode of Adjust Linestring Elevation is designed to help you correct these issues on either individual elements (an arc return or a single island) (Plane Mode) or all lines of a parking lot to a grading framework surface (Surface Mode).

Filled out command dialog looks as follows

Interpolated points on arcs

This setting allows you to choose from the following options to determine how the elevation nodes are added to arc segments along the line.

None - does not add any additional elevation nodes to arc segments
Angle - uses an angle increment computed at the arc radius point to place elevation nodes in arc segments, i.e. if your arc subtends a 45 degree angle at the radius point and you select 15 degrees as the interval, you will get elevation nodes at the 0, 15, 30, and 45 degree locations. Note that if your arc subtended an angle of 47.5 degrees that you would have a short 2.5 degree segment at the end of the arc in this scenario.
Arc distance - uses a distance along the arc to place elevation nodes in arc segments, i.e. if your arc is 50’ long and you select 10’ arc distance then you will get elevation nodes at the 0,10,20,30,40 and 50’ points along the arc. Note that if your arc was 53.6’ long that you would have a short 3.6’ long segment at the end of the arc in this scenario.
Arc to chord - uses an arc to chord separation tolerance to determine the location of the elevation nodes. If you enter a value of e.g. 0.01 then you will get more nodes than if you enter a value of 0.05. The value you enter is the maximum distance allowed between a chord line drawn across the arc between one elevation node and the next, and the arc at the chord mid point. Smaller values = more nodes along the line, larger values = less values along the line. The benefit of this method is that you will get a uniform number of segments on the same radius arcs, and you will get more segments on tighter radius arcs and less on looser radius arcs allowing the software to adjust the number of elevation nodes automatically based on a single tolerance value.
Number of segments - divides the arc length into a number of equal segments i.e. if your arc is 50’ long and you elect 4 segments you will get 4x 12.5’ segments between the elevation nodes.

Pick the method that you wish to use. Number of segments or Arc to chord are popular settings for arcs in e.g. Parking Lots because they both create a uniform spacing of points around arcs that will create more uniform triangulation in surfaces that are generated later from the linework.

Once you have selected the interpolation method, enter the values that are requested to support that method i.e. if you select Number of segments, enter the number of segments that you require, if you select Arc to chord, enter the Arc to chord distance that you require etc.

Plane Definition

Select 3 points that define the plane you want to use. Each point / location that you select needs to be a 3D location. The plane will be created once you have selected the line that you want to elevate so that the plane extends beyond the limits of the line that you select.

Reset plane after adjusting linestring

Check this checkbox if after each linestring elevation adjustment you want to define a different plane for the next line that you want to elevate.

Linestring

Select the line that you want to adjust the elevation of

Portion

Select which portion of the line that you want to elevate - choose from the different portion options i.e. All, Start to Location, Location 1 to Location 2 or Location to End.

Once the Portion method has been selected, select the necessary locations to define the range. Note that Start and End are already known so you will only need to select one location for the Start to Location or Location to End modes. For Location 1 to Location 2 mode you will need to select 2 locations.

Secondary Adjustment

If you wish to apply a secondary elevation adjustment over the selected portion of the line, you can choose the Adjustment mode (from None, Constant or Range), and then define the values for the secondary adjustment in the normal way.

Results of the process

You can clearly see that the warping at each curved corner has now been corrected and that the plane has now been supported through al of the arc sections through the addition of the extra vertical controls to the curved sections of the line. Note that the additional vertical controls are equally spaced around the curved sections resulting an more uniformity in the surface model created from the line.

In this second example (shown below) we are given spot elevations at the PT / PC on the bullnose of an island at the end of a parking bay and additional spot elevations at the IP point of the curves and then a further elevation point at the back of the parking bay. The intent of the engineer is clear that there is a slope of 0.4’ over the 20’ from the nose of the island to the back of the parking bay. The arc radius is 4’ so at the PC / PT points of the arcs not provided, the elevations should be 100.08 (4’ x 0.4/20), however if we query the line at those same locations having been elevated as provided, the elevation at those points is 100.11 i.e. 0.03 higher than the engineers intent. In addition that difference also shows up in the curved sections as a crest or sag in the same way as in the previous example.

So the filled out dialog for Plane mode in this example will look as follows

On execution the result is as shown below

Here is the colored elevation view of the island surface - again showing that the warping of the surface around the curved sections has been corrected.

Before correction

After correction

Spot Mode

The spot mode provides the ability to add elevation points to 2D or 3D lines at the locations where they are provided in the plans. When you add a spot elevation to a line, it allows you to create the spot location as a VPI or as a 3D node in the line.

Notes

If you create nodes as VPIs, they are placed on the line at a specified distance along the line and at a defined elevation. Be aware that if there is any likelihood that you may change the shape of the line at a later stage e.g. if you grip edit the start of the line, then the VPIs will move along the updated line so that they retain the same distance along value that they were defined with. This can be both good and bad, depending on how much editing that you are likely to do after the application of the elevation adjustments.
If you create nodes as 3D nodes, the location selected will become a horizontal node with an elevation. The benefit of 3D nodes is that the 3D nodes will not move if the line is later edited unless you move the specific node in question. The downside of 3D nodes is that if they happen to fall in mid arc, the arc will be split into two parts at the 3D node location. This in itself is not a big issue unless you intend later to edit the arcs to change their shape or location, if you need to do that you will have two arcs to manipulate rather than one, and it will likely be quite difficult to maintain tangency between the two segments as a result.

Video Demonstration

The Spot mode dialog looks as follows

Use elevation formula

Often on plans the elevation values will be truncated to minimize the space required for the text on the drawings i.e. if the elevation is 4035.47 they may display it as 35.47 to save that space. Additionally, keying in 4035.47 type values for all of the elevation points in a project is a lot of data entry, if all the elevation values are in the 4000 range you can use an Elevation Formula to minimize the data entry i.e. you can enter a formula of {Z}+4000 and whatever value you type in will have 4000 added to it before applying it to the linestring being edited.

Check the checkbox and enter the elevation formula you require. You can use the usual +, -, / and * as math operators. The Z value that you enter or click is always presented as {Z} in the formula. Do not use spaces in the formula.

Auto apply on elevation change checkbox

Check this checkbox to auto apply the elevation values on pressing Enter after typing in a value or on click of a 3D object or text item displaying the elevation value. Note that if you click on an elevation point of 4035.46 and you have an elevation formula of {Z}+4000 you will double up the 4000 and make 8035.46.

If the elevation that you enter or click is different from the previously entered value (at the last location) when this checkbox is checked, the elevation will be automatically applied on accepting the entry with Enter or clicking the elevation text etc. When not checked, you will press Enter to accept each value selected or entered. If there are two successive points with the same elevation value, you will need to press enter to accept the second value manually.

Point type

Select the elevation node type that you want to create - choose from VPI (Vertical Tab of linestring editor) or 3D point (Horizontal tab of the linestring editor). Note that 3D nodes insert a line node as well as an elevation whereas VPIs only add an elevation at the selected location.

Linestring

Select the line that you want to elevate

You can switch the line direction arrows On and Off using the show direction button at the end of the linestring selector field.

Set the Auto advance button at the end of the line selector field to enabled (orange tinge), that way each elevation entered will be for the same line until you change lines on completion of the line.

Location

Select the point along the line that you wish to elevate

Note that your Snap modes are going to be important in this process. Typically you will need End Point, Near Point and Intersection Point snaps running to create elevations at the correct locations along the line. Click Snap in the toggle buttons at the base of the graphics screen area of TBC to access the point snap modes.

Elevation

Type in the elevation of the node or click on a piece of text that contains the elevation value or a 3D object from which the elevation can be determined (point, line etc.)

You can also use the right click options to extract elevations from other lines or locations e.g. Along Line snap etc…

Hot Keys

The command loops continuously between location and elevation fields. When you want to change lines press the N key on your keyboard to start a new line or click in the Linestring field of the dialog to initiate a new sequence of elevations on a new line.

Surface Mode

The Surface Mode has been created to elevate lines to a surface model, however in this process rather than draping the line over the surface model and elevating all of the straight and curved sections where the lines cross the Triangle sides of the surface model, we create a uniform number of points in the curved sections of the lines only to elevate the line to the surface but only the curved sections and only at the interval or arc to chord etc. locations.

This process has been created to improve modeling of curb and gutter lines in parking lots, where the engineers intended surface shape is defined by a “Grading Framework” that represents the planar surfaces and slopes intended by the engineer.

Video Demonstration

In the following video we show how to create the Grading Framework lines and surface for a Parking Lot, how to build a surface model from those lines and then how to elevate the Curb and Gutter lines to that grading framework surface. We also show how to use the Multi-Offset Line command to create the other lines of the curb and how to make a surface from the overall results.

First step in this process is to visualize the engineers intent and to use the elevation call outs to draw the grading framework lines in 3D, and then to create a surface from those grading framework lines.

The second step is to elevate the Curb and Gutter lines to the grading framework surface which will ensure that the vertical shape of the curb lines is following the grading framework

Final step of the process is to use the multi offset line command to create the Flow Lines (FL) and Top Back of Curb Lines (TBC) from the Edge of Pavement Lines (EOP).

The command dialog looks as follows for the Surface Mode of operation

Interpolation points on arcs:

This will divide the arcs of the selected lines into a number of segments with VPIs at each of the segment end points based on the mode selected. The more segments you use, the closer the curb line will be to the designers intended planar grade.

You can choose one of the following modes to determine the intervals for each arc segment

None - this will not subdivide the arcs of the selected lines
Angle - this will subdivide the arcs into segments of equal angle e.g. 5 degrees
Arc distance - this will subdivide the arcs into segments of equal length e.g. 1.0’
Arc to chord - this will subdivide the arcs into segments where the chord is always less than a specified tolerance from the arc segment at its mid point. This increases the number of segments when the radius gets smaller or the arc gets longer.
Number of segments - this divides the arc into a defined number of segments of equal length e.g. 4 segments.

Note that with Angle and Arc distance mode, there will always be the potential for one segment that is shorter than the others, this is the “remainder” segment i.e. if the Arc angle of the source line is 92 degrees and you choose a 10 degree angle then one segment will be 2 degrees. Similarly if the Arc length is 103.5’ and you choose 10’ then one arc segment will be 3.5’ long.

Once you have selected the method to use, enter the values required to define that method e.g. For Number of segments method enter the number of segments that you require etc.

Surface:

Select the surface model from which the elevations will be determined. This will be the grading framework surface in most situations.

Linestring:

If you have the Portion setting below set to All then you will be able to select multiple lines here. If the Portion setting is set to Start to Location, Location 1 to Location 2, or Location to End you will only be able to select a single line here.

Portion:

The portion refers to the range of a line or lines that you want to adjust. The options are

All - the entire length of a line or a number of lines that you select
Start to Location - the start of the line to a point along the line
Location to Location - a range between two points along the line e.g. from station 300 to 600
Location to End - from a point along the line to the end of the line

The mode that you select here determines whether you can select a single line or multiple lines for adjustment at the same time. When All is selected you will be able to select multiple lines for adjustment. When All, or any of the other options is selected you can select a single line only for adjustment.

Once you have selected your Portion mode, select the locations necessary to support that selection e.g. Location 1 and Location 2.

Secondary adjustment (Delta values):
If you wish to apply a secondary elevation adjustment to the lines once they have been elevated to the surface you chose, you can apply that here. You can choose from the following options

None - No additional elevation adjustment
Constant - A constant elevation adjustment over the adjustment range of the selected line or over the entire length of all selected lines
Range - Applies an elevation adjustment at the start of the line and a different adjustment at the end of the adjustment range to apply a transitional adjustment over the range on a single line. The range mode makes little sense in most situations where you are adjusting multiple lines at the same time.

Use Case Notes

The location fields allow math functions, so for example for location 2 you could click on the end of the line to derive the lines total length and then enter -200 after the displayed value to move location 2 200’ back up the line.

Header Bar Commands

The following commands have been added to the header bar of the command dialog providing you with quick access to the tools that you will likely need when working with the adjust linestring command

Help
RPS Settings
Takeoff Lines
Smart Edit
Convert to Linestring
Edit linestring
Create Point
Break Line
Smart Join
Insert Line Segment
Explore Object
New Profile View

Note that if you hold the Shift key down when you click the New Profile View command, the currently selected line will be computed in the plane of the currently open profile view allowing you to see two or more lines projected into the plane of the original line used to create the profile view.

Apply
When you tap apply, the linestring elevations will be adjusted and the command will ready itself for another selection set and repeat process execution. If you do not want to make a second selection and repeat the process tap Close to finish the process.

Close
Closes the command with no further execution.

Feedback and Enhancement Requests

If you would like to provide feedback on the use of the Adjust Linestring Elevation command or to request enhancements or improvements to the command please click “reply” below!