Multi-Offset Line Command

D_MultiOffsetLine_600ppi   Multi-Offset Line

Command Licensing and Default Menu Location

  • The Multi-Offset Line command is part of the RPS Modeling Toolbox
  • The command is located on the Modeling macros menu ribbon
  • The command is located in the Corridor menu group

Command Description

Multi-Offset Line is a template driven command that creates multiple offset lines from one or multiple source lines in a single step using offset / slope, offset / delta elevation and offset / elevation instructions. The command leverages the linestring optimizer, point creator and slope designer technologies released in other commands to create multiple lines on target layers that can be automatically combined into any number of surfaces.

The command is ideal for creating curb and gutter, site roads, barriers, trenches, foundations and footings and other similar surface elements for both finished grade and multiple subgrade surfaces. It can also be used with measured linework to create As Built linework for associated features e.g. from a measured Top Back of Curb you can create linework for Flow Line and Edge of Pavement that may be required for reporting purposes.

Command Interface Description

The Multi-Offset Line command dialog looks as follows

Select the linestrings that you wish to create the offset lines from. For advanced selection methods click the Options button to access Advanced Select, Select by Layer, Select by Elevation etc.

Show direction checkbox:
Check the checkbox to see the line direction of the selected lines. The template defines the left, right or both sides of the line elements, and the placement is dependent on the direction of the lines selected. The line direction of open lines is the main concern here because the command automatically checks for closed lines and if closed, inside the closed line is treated as the right side of the line. If the show direction arrows indicate that one or more lines are in the wrong direction you can deselect them and process them with a second step using the mirror template option (see below), or you can run the Show Direction command and reverse them prior to running the Multi-Offset Line command.

Limit stations checkbox:
If you wish to apply the selected template over a station range of the source line, check the checkbox and then select a Start and End station.

Note that if you are chaining templates together along the source line, it is a good idea to leave a small gap of e.g. 0.02’ between the applied templates to aid modeling the location where the two templates come together. i.e. if your range for the first template is 50.00 to 80.00 then the next range could be 80.02 to 120.00 etc. You can then easily add link linework to connect the templates as needed using e.g. Takeoff Lines command (with the 2 point line mode enabled).

Point creator style:
The Multi-Offset Line command utilizes the Point creator style to determine the locations along the source lines at which to compute the offset line locations. For more information on Point Creator Styles please refer to the Point Creator command documentation - Click Here

Select the point creator style that you wish to use - we recommend the use of the Point Creator Settings file (download below) and the Slope - Offset Lines style.

Download the Point Creator Settings file, unzip the file contents and place the file in your RPS Settings folder. Your RPS Settings folder is defined in the RPS Settings command (accessible from the header bar of the Multi-Offset Line command) under File Locations. (1.4 KB)

Note that the point creator style, the optimizer settings and the internal / external corner modes are all stored with the multi offset line template definitions, and are recalled and set by the Template. When running the command with a selected template you can override any of the predefined settings for the next execution of the command, and unless you “Save” the changes, the template definition will not be updated.

Each offset line is computed from the source line based on the intervals and node locations as defined in the location style selected (Point Creator Style). Once the offset line is computed, it can be optimized to re-compute the horizontal curvilinear geometry of the offset lines from the chords computed for the offset lines. The vertical geometry can also be optimized to remove unnecessary grade breaks (filter out vertices along straight slopes) and to add in vertical curves at grade breaks greater than the linestring optimizer tolerances e.g. 0.5 degrees, to smooth out the vertical geometry for slipform paving and curb and gutter machine control operations.

For more information on the linestring optimizer Click here

You can elect to optimize the horizontal components of the created linework, the vertical components or both horizontal and vertical components.

The benefit of optimizing the linework is that you return it to curvilinear geometry thereby removing chords on curved sections, the number of horizontal and vertical control points (nodes) on each line is minimized thereby making the data more efficient for modeling purposes, and the control of the surface modeling that uses the created linework is back under the control of the breakline approximation parameters defined for surface modeling as defined in Project Settings - Computations - Surfaces - again making the surface modeling more efficient and more accurate.

Note that the template definition allows you to reference any line to either the source line or any other line that is being created by the template. No matter how you define the values, the offset lines are all computed from the source line, and therefore leverage the curvilinear nature of the source line fully during the computation phase, thereby increasing the accuracy of the resulting linework.

The optimizer settings used by this command are as follows

Horizontal Tolerances:

Line Tolerance = 0.005’
Arc Tolerance = 0.005’
Max Radius = 10000’

Vertical Tolerances:

Minimum Angle = 0.5 Degrees (30 minutes of arc)
Maximum Offset = 0.02’
Maximum Length = 10.0’
Ignore VPI on sharp corners = Yes

Internal and External Corner Modes:

The Multi-Offset Line command leverages the Slope Designer controls for modeling around internal and external corners. For more detailed information on the following settings refer to the Slope Designer command documentation - Click Here.

Internal corner mode:
An internal corner of a line is an angle corner where the angle is less than 180 degrees. Typically on an internal corner you want to compute the offset line location using the point at which the inbound line segment intersects the outbound line segment. The alternative approach is to create an angle bisector and then find the locations at which the inbound and outbound line segments intersect the bisector (which generates a closest and furthest alternative - you can then use the closest, furthest or average of the two as the point at which the offset line will pass through.

There are therefore multiple possible solutions for an internal corner (at least 4), the commonest being the Intersection mode. The other three modes can be used in corner case situations as required.

Select the Internal corner mode from the following options

  • Intersection mode - finds the intersection of the inbound and outbound line segments at the offset corner. Note that the intersection point will not necessarily be at the bisection angle of the corner. This is the most commonly used option and is the default behavior.

  • Chamfer mode - creates two points with the correct elevations transferred from the source line (at the slope or elevation delta) with a small chamfer between them to transition elevation over a short distance at the internal corner. The chamfer ends are also connected to the source line corner point to ensure correct triangulation in the corner, thereby creating correct cross slopes for slip form paving all the way into the corners. This mode is ideal for creating the surfaces required for Trimble curb and gutter machine models (they require a surface model and a line for each curbline).

If you do not compute the internal corner using the Intersection or chamfer mode, if the angles are less than or greater than 90 degrees there are two possible solutions for where the intersection of the two offset segments intersect the corner angle bisector. We offer the “closest”, “furthest” and “average” options here as alternatives to the intersection mode.

  • Closest mode - uses the closest intersection point of the inbound and outbound line segments with the angle bisector line.
  • Farthest mode - uses the furthest intersection point of the inbound and outbound line segments with the angle bisector line.
  • Average mode - finds the closest and furthest intersection points and computes the average position on the angle bisector line.

External corner mode:
An external corner on a line is an angle corner where the angle is greater than 180 degrees. For external corners you have three options to determine the shape of the line around the corner - Chamfer, Radial and Tangential Extension. The commonest options are Tangential Extension and Radial.

  • Chamfer - this computes the perpendicular offset to the inbound segment and the outbound segment at the angle corner and simply creates the offset line by joining those two locations across the corner

  • Radial - this computes a series of points around the corner at even angular intervals to create a radial / curved corner.

  • Tangential Extension - this projects the inbound and outbound segment to the point at which the two lines intersect.

Mirror template checkbox:
If your template for the multi offset line creation process is defined for the right side of a line, and the line is currently drawn in the wrong direction to be able to use the right side template, you can simply check this checkbox to mirror the template definition.

There are two types of template that we envision.

The first is a complete cross section e.g. of a subdivision road or for a complete symmetrical jersey barrier etc. where the template covers both the left and right side of the line requirements in one template. These types of template should not be mirrored.

The second is a template that is defined for either Right or Left side use e.g. a Curb and Gutter section where the template is defined for the right side only or the left side only e.g. the source line could be the Edge of Pavement and you generate offset lines for the Flow Line, Top Face of Curb, Top Back of Curb and Sidewalk to the right side of the edge of pavement. These types of templates are the ones that you can mirror, thereby saving the need to define both a left and right side template for each definition.

The mirror checkbox simply reverses the sign of the offset values defined in the template i.e. if the Flow Line of a curb section is 1.5’ to the right of a line at -4% then the mirrored version would be -1.5’ from the line at -4%. Slopes, Delta Elevations and Elevations are unaffected by the mirror process.

Override name checkbox:
When enabled, this option will allow you to override or extend the names of the lines created by the template definition e.g. if the name defined in the template for a line is GWB then in the definition field here if you enter {N}-1A will add a -1A to the name of all lines created by the template i.e. GWB-1A. If you enter WALL then all lines will be called WALL etc. The {N} allows you to retain the default name defined in the template. You can add prefix, suffix or a complete replacement name.

Override layer checkbox:
When enabled, this option will allow you to override or extend the names of the layers created by the template definition e.g. if the name defined in the template for a layer is Finished Grade then in the definition field here if you enter {L}-1A will add a -1A to the name of all layers created by the template i.e. Finished Grade-1A. If you enter DESIGN then all Layers will be called DESIGN etc. The {L} allows you to retain the default layer name defined in the template. You can add prefix, suffix or a complete replacement layer name. Note that adding a Prefix or Suffix is a better choice when you have two or more layer names defined by the template.

Override surface checkbox:
When enabled, this option will allow you to override or extend the names of the surfaces created by the template definition e.g. if the name defined in the template for a surface is Finished Grade then in the definition field here if you enter {S}-1A will add a -1A to the name of all surfaces created by the template i.e. Finished Grade-1A. If you enter DESIGN then all surfaces will be called DESIGN etc. The {S} allows you to retain the default surface name defined in the template. You can add prefix, suffix or a complete replacement surface name. Note that adding a Prefix or Suffix is a better choice when you have two or more surface names defined by the template. Use this option if you want to create component surface elements that are not linked together e.g. if you have a template defining a wall and the wall can be found between stations 100 to 350 and from 825 to 975 you likely do not want the two wall surfaces joined together so add -1A to the first wall and -1B to the second wall so that they are formed as unique surfaces.

Draw end lines checkbox:
When enabled, this option causes end lines to be drawn (lateral breaklines) perpendicular to the linear features created by the template at the start and end station of the template placement. This assists with model building when you are chaining templates together longitudinally e.g. different height wall sections or curb - gutter - sidewalk and gutter - sidewalk - driveway combinations.

Note that the end lines will only be created if the template is defined using “sequential elements” where each subsequent element is computed from the prior element in the template. If the template is defined with all elements are referenced to the source line then the end lines option will not be executed.

Template Selector

Templates are a set of instructions that collectively define the set of offset lines that you wish to create. The instructions define a series of offset and slope, offset and elevation or offset and delta elevation pairs that are used to create the offset lines. The computed lines can have a name, a layer and they can be assigned to a surface model. You can define as many instructions in your template as you want. The number of surfaces is also unlimited so you can define both finished grade and subgrade elements all within a single template.

Templates can be created directly within the command dialog, or they can be created in the RPS Settings command accessed from the header bar of the multi offset line command. When you create templates from the command dialog, you have the ability to either manually enter the instruction lines or you can draw the template in the plan view and then select the drawn lines to define the template instructions. When you define the templates using the RPS Settings function, you can increase the size of the dialog to maximize screen real estate when defining complex templates, however in this mode you cannot use the Load Lines function because graphical interactions from this type of command dialog is prohibited by Trimble Business Center.

No matter how you create the templates, the Templates are stored in your RPS Settings folder within the RPSMultiOffsetLineTemplates folder. The RPS Settings Folder is defined by the File Locations settings in RPS Settings.

Within the Multi Offset Lines folder you can create sub folders and then files in which you can create your templates. There is no limit to how many folders or sub folders or files that you can create. The approach here has been created to facilitate the development of template libraries that manage the typical details from DOTs., Municipalities, specific projects, your favored defaults etc.

For example most DOTs publish standards for Curb and Gutter, Barrier, Noise Walls and other standard shape objects. In the Template system you can create the following structure

Colorado DOT Folder
   Curb and Gutter Standards Folder
      C&G Standards File
            C&G Type 1 Template
            C&G Type 2 Template
            C&G Type 3 Template
   Barrier Standards Folder
      Barrier Standards File
            Barrier Type 1 Template
            Barrier Type 2 Template
            Barrier Type 3 Template

You can have Folders for all of the DOTs or Municipalities that you work with as well as some generic templates for other use cases in a General Use Folder. In this way you can develop your library and use it on all your projects and also share your libraries with other team members quickly and easily.

The Template selector lets you browse your library to find the Folder / Sub Folder / File and Template that you are looking for

Once you have selected a template, the template details are displayed below in the Template Viewer.

Within the Templates manager, you can use the Right Click menu to do the following

Deletes the currently selected Folder, File or Template. If you select a Folder, all Subfolders, Files and Templates that are housed within that Folder will be deleted. If you select a File, all Templates housed within that File will be deleted. If you select a Template just that template will be deleted.

As you develop and evolve your template library, it is inevitable that you will want to rename your Folders, Files and Templates so that they are easier to find and utilize. Select the Folder, File or Template and use the Rename function to change the name of the selected item. The Rename function will also let you change the Description of the template or file when a template or template file is selected.

Add File:
Within any folder you can have one or more template files. A template file can contain one or more templates. You can choose how you want to structure your template data e.g. you can have all of your curb and gutter typicals for a DOT in a single Curb and Gutter file, or you can have each curb and gutter typical in its own file - the choice is yours. To add a template file to a folder select this option.

Add Folder:
Folders can be used to organize your template library. You can design your library structure exactly as you need / want it. The structure is built around Folders, Sub Folders, Files and Templates as the building blocks. You can keep your folder system relatively flat / shallow, or as deep as you want it to be. To add a folder to your library, select the parent folder and then select this option to create the new folder or sub folder.

Save Template:
Once you have started the process of creating a template, you can use this option to save the template in its current state. Selecting Save will update the template definition along with the “sidecar settings” including the point creator styles, Optimizer settings and the internal / external corner modes.

Copy Template:
If you want to create a copy of a template, select the template that you wish to copy and then select Copy Template to create your copy. Once copied you can then browse to the folder or file into which you want to paste the template.

Paste Template:
If you have copied a Template you can now find the folder and file into which you want to paste the copy data. When you paste the template, you can define a new name and description for the template copy you are creating. Once copied, you can then edit the template definition and save the template to create a modified version of the template.

Note, at this time there is no Save As for template creation. Use the Copy and Paste function to make a copy and then edit and save the copied template.

Load Lines - Source or Load Lines - Sequential:
When creating a template, you can draw a template shape precisely in the plan view using one or more polyline objects. Each node that you define in the polyline becomes an offset line in the template you are defining.

  • Name the lines that you draw with the name that you want assigned to the lines to be created from the template.
  • While drawing the lines, place them on the layers that you want in your template definition. The layer name on which the lines are drawn is used to define the target layer for each of the multi offset lines derived from the template.
  • The layer name is also used to define the target surface for the multi offset lines derived from the template. For example if you want a Finished Grade surface / layer and a Subgrade surface / layer, create two layers called Finished Grade and Subgrade respectively. Then draw a separate polyline on the Finished Grade and Subgrade layers. Note that the Finished Grade line may use the source line as its starting point whereas the subgrade surface may start vertically below the source line. The Subgrade line should still have it’s first node as the source line location - see below for an example - different colors represent different layer / surface definitions.

In the above example, we want to create the two surfaces shown with the Orange lines, using the two polylines that represent Finished Grade (Red) and Subgrade (Blue) from the source point at the origin of the two polylines (Green Spot) to create the multi offset lines (Pink Spots) that form the two surfaces (orange lines). Note that we do not want to create the vertical blue line in the subgrade surface, however we do need that element in the subgrade polyline in order to reference the nodes back to the source line (Green Spot). Remember Multi Offset Line is creating 3D lines primarily, those lines can be placed on layers and can be incorporated in surfaces - each line can be assigned to a single surface in the template, however those lines can be added to other surfaces as needed after creation using the Add / Remove Surface Members command.

Also remember that two lines that will be incorporated in the same surface should not occupy the same location at different elevations, they need to be offset from each other by the verticality tolerance of triangles in the TIN Model - we recommend 1mm or 0.01 or 0.02’. In addition you are also applying optimization to the chorded lines that are being computed by the Multi Offset Line command to return the lines to curvilinear features - the default tolerance of the horizontal optimization is 0.005’ so this can push lines closer together than you would have with “perfect” lines in curved sections so you need to allow for that.

When you use the Load Lines function, all of the line nodes are converted into template instructions. You can load lines using the Load Lines (Source) or Load Lines (Chain) options.

The Load Lines (Source) will compute each node as an Offset / Delta Elevation from the Source Line.

The Load Lines (Sequential) will compute each node as an Offset / Delta Elevation from the previous node in the selected line. We recommend the use of Load Lines (Sequential) for most template definitions.

Once loaded into the template editor / viewer you can change the values to Offset / Slope or Offset / Elevation as needed.

Sketch Templates

Using the above method you can sketch a shape in plan view, use the Load Lines (Sequential) function to add the lines to a template, and then correct the values to be the specific values that you require in the template. By sketching the approximate shape on a layer, you are able to automatically create all of the instructions / nodes with their target layer and surface and reference node definition, you can then quickly update the offset and elevation / slope values as required.

Template Viewer and Instruction Editor:
The template view is showing you a copy of the source template that you selected in the Template Manager and is coming from your template library. You can select instructions in the template and edit them to modify the default template to meet your current requirements. Changes that you make here do not affect the template stored in the library unless you click the Save button. If you do not press Save, the changes are simply short term overrides to your template.

For example you may have a subdivision road template that has a 12’ pavement section. For the current project, the roads are defined with a 14’ pavement section. You can still use the template from your library and then override the 12’ offsets with 14’ offsets for the edge of pavement lines without changing your original template. Alternatively you could copy the template and paste it as a new template, modify the values and then save the template to store the changes for future use.

To edit an instruction line in the template, select the line by clicking anywhere in the row of values. The currently selected row then populates the Current item information in the editor line below the template viewer.

To edit an instruction, click in the cell that you wish to change and enter the override value. The values of a template instruction include

The reference line is the line from which the offsets and slopes, elevations, delta elevations are computed from. Any instruction can reference a line created by any other instruction in the template. There is no specific or sequential order necessary in the template i.e. the third instruction in the template can reference a line being created buy the twelfth instruction in the template. The order of the instructions in the template are more for your benefit, they are not important to the command itself.

You can move instructions up and down in the list without fear of breaking the template. If Reference = Source then it is referring to the line(s) selected to which the multi offset line template is being applied.

Multi Offset Line can be applied to one line at a time e.g. to create a barrier wall along a centerline or to 100 lines at one time e.g. to create curb and gutter for all of the edge of pavement lines in a parking lot.

Each instruction that you create is referenced by the name that you define for the line e.g. FL or EOP or TFC or TBC etc. As you create each instruction, the first instruction to use FL creates line reference FL (1). The second time you use the same line name becomes FL (2) etc. All of the lines that you define get added to the potential reference line list - you can select whichever line you wish as the reference.

Note: When the offset line command executes, the offset of the line from the selected line for the command is determined from the template. Each offset line is actually computed from the selected line, not from the line name referenced as the reference line. This means that all of the lines computed are derived from the selected lines geometry. All slopes and delta elevations are computed into a delta elevation from the selected line in the same way. The only value that is nor recomputed is a specific elevation defined using =Elevation in the Vertical field of an instruction e.g. =122.35 defines a specific elevation value.

Each line defined in the instruction list is given a name. The name is made unique through the automatic addition of the (number) to the name that you input i.e. if you name a line FL it will be come FL (1) or FL (2) etc. to make it unique in the name list.

This is the offset from the reference line used in the instruction. e.g., the FL would be 1.5’ from the EOP reference line. Enter a positive value to offset to the right and a negative offset to offset to the left.

This the is the vertical control for the line being created. You can enter the value as a

  • Delta elevation: Enter the value as e.g. 0.5 or -0.5
  • Slope %: Enter the value as 2% or -2%
  • Ratio: Enter the value as 2:1 or 1:2 or -2:1 or -1:2 depending on your Run to Rise or Rise to Run settings in Project Settings.
  • Specific Elevation: Enter the value as =102.36 for a specific elevation of 102.36

A positive value for delta elevation or slope is above the reference line, a negative value is below the reference line.

You can select a layer from the pull down list of layers that exist in the current project already, or you can type in your desired layer name and the layer will be created whenever the template is used. Note that a new layer will be created in the layers section of your project and cannot currently be assigned to a layer group. If you wish to use specific layers and layer groups, define those first in your project template and then you can select the layer from the pull down list and the layer group will be automatically assigned.

You can select the surface from the pull down list of surfaces or select “none” from the list if you do not wish this line to be added to a surface automatically. You can also type in the name of the surface that you wish the line to become a member of, and that surface will be created automatically when the template is used for the first time in a project.

Note: If you are using Takeoff workflows, the Takeoff Surfaces (Layer Based Surfaces) are created using the Categorizations assigned in the Takeoff Process. If you are creating lines that you wish to use in the Takeoff process, we recommend that you create the Layers and Layer Groups in your project template, and then categorize those layers in the Takeoff process and save your updated project template. You can then select the required layers in the layer values defined above, and then select none here for the surface. That way the lines created will be categorized and then added to the Takeoff Surfaces when you use Build Takeoff Surfaces. Alternatively, if you select a Takeoff Surface here, the lines that you create will be added as additional members to the Takeoff Surface regardless of which layers that you place them on. Either way works.

Advanced Editing Capabilities:
If you right click in the template viewer, you will be offered the following options.

  • Add a Row - This adds a new row below the currently selected row in the list of instructions. The edit line is automatically populated with the default values (which duplicates the layer name and surface name of the instruction over which you right clicked or had selected)
  • Delete a Row - Deletes the row over which you right clicked
  • Move Up - Moves the row over which you right clicked up in the list
  • Move Down - Moves the row over which you right clicked down in the list
  • Duplicate - Duplicates the row over which you right clicked at the bottom of the list

These edits are also available in the Template Editor within RPS Settings. Remember the changes that you are making here are short term overrides that are not saved until you click the Save button. If you wish to change the template definition, click the Save button.

Command Tips:
The command Tips show you how to get help and support using the F1 key, they also show you any shortcuts or command tips for this command. You can minimize the command tips when you no longer need to reference them by clicking on the image button

Multi-Offset Line Template Editor in RPS Settings

The Multi-Offset Line templates are all created using the template editor in either the command dialog or in RPS Settings. To use the RPS Settings method, open RPS Settings by clicking on the RPS Settings button in the header row of the command.

Select the Multi-Offset Line Templates option within the RPS Settings dialog

The template manager and template viewer / editor here work in an identical manner to the methods defined earlier in this help document, the only difference is that the Load Lines functionality is not available here, and that the layout of the additional settings (point creator settings, optimizer settings and internal / external corner modes) are shown below the template viewer / editor rather than above.

Click OK to save the changes and close RPS Settings to return to the Multi Offset Line command.

Click Close to close the RPS Settings and return to the Multi Offset Line command without saving the most recent unsaved changes to your templates.

Executes the command, creates the offset lines and surfaces and prepares the command for a further selection process and execution.

Closes the command without further execution.

Video Demonstration

The following video shows how to utilize the Multi-Offset Line command

Update v1.05 Feb 21 2022
The following video covers the v1.05 enhancements made to the initially released command including

  • Limit station range
  • Override line names
  • Override layer names
  • Override surface names
  • Create end lines
  • Load sequential mode (Template creation)
  • Line naming using load line names
  • Always create the source line when using Load Lines

Update v5.70 June 2022
The following video covers the v5.70 update enhancements that introduced the chamfer internal corner mode to better support modeling needs for Trimble slipform paving systems for curb and gutter operations. The chamfer corner provides the means to create a surface model that holds a 0% (or other) cross slope all the way into a corner as shown in this diagram

Feedback and Enhancement Requests

If you would like to provide feedback on the use of the Multi-Offset Line command or to request enhancements or improvements to the command please Click Reply below