2D Point Feature

Contains no elevation (Z).  2D Point Features are defined and stored in plan model.

3D Geometry

3D geometry is created in 3D model by mathematically combining the horizontal and vertical geometry to create 3D elements.  These 3D geometry elements in turn define a design model.

3D Model

This is created and managed automatically.  User can interact with it but this is not usually required.  The mathematical combination of Plan Geometry and Profile Geometry is stored in the 3D model.

3D Point Feature

3D points can be defined in plan model or 3D model.  They are stored in 3D model but represented in both plan and 3D.

Active Object

The current object to which is added all geometry which is created.

Active Profile

Of the multiple possible profiles for an element, the active profile is the one used for design.  The active profile is combined with the horizontal geometry to build a 3D element which is used in the 3D model.

Active Terrain Model

One terrain model can be designated as “Active”.  The active terrain model is the one used to display “existing ground”; in other words the one which displays automatically in a profile model when it is opened.  The active terrain model is also the one which is targeted by side slopes unless the template defines a different target by name.

ALG

A legacy (proprietary) InRoads file containing coordinate geometry information, superelevation, and alignment information for a specific geometry project.

Alignment

A linear feature which serves the special purpose of defining the centerline or baseline of a roadway.

Apply Linear Template

Applies a corridor template along a feature while hiding some of the complexity of creating a corridor.

Apply Surface Template

Applies a corridor template to a terrain model for the purpose of creating components (such as pavement layers) under the terrain model.

Arc Definition

Curve definition method generally used in roadway applications. The radius R is used to define the curve and is defined by the equation R=5729.58/D where the degree of curvature D is the central angle subtended by a 100-foot arc.   Set in the Design File Settings > Civil Formatting under Radius Settings.  See also Chord Definition.

Aspect

An angular measure of the direction that the face of a surface is oriented. The format of the value is dependent on angular settings In the DGN file.

Base Geometry

In many instances the geometry element will be trimmed. The original (or base), untrimmed element is always preserved as it is the storage for the rule.

Boundary  (Terrain Model)

Used to constrain the external boundary of the terrain model. No triangles are created outside the boundary. In addition, any point data outside the boundary is ignored.

Break Line

A surface feature consisting of a collection of spatial coordinates that have an implied linear relationship. No triangle side (in the triangulated surface) can cross over a break line.

Break Void

A closed area of missing or obscured data that uses the elevations of each vertex, while the void lines between successive void coordinates are inserted as break lines. Therefore, break voids change the slope and elevations of the TIN surface.

Cardinal Points

One of the points used to define the geometry of an alignment. Cardinal points include PC, PT, PI, and CC points for horizontal geometry and VPC, VPI and VPT for vertical geometry.

Centroid (triangle)

Geometric center of a triangle in a terrain model.

Chord Definition

Curve definition method generally used in railway applications.  The radius R is used to define the curve, and is defined by the equation R=50/SIN(0.5*D) where the degree of curvature D is the central angle subtended by a 100-foot chord.  See also Arc Definition.

Civil Cell

Used as a mechanism to preconfigure commonly used complex geometric layouts.  These layouts will commonly be stored in DGNLIB files for reuse across multiple projects but it is possible and sometimes useful to store directly in an active DGN file for use in that single location.  The civil cell will contain horizontal geometry and can also contain the vertical geometry.

Civil Message Center

Used to display a continuous updating log of Civil messages, including warnings and errors. As errors and warnings are resolved, they are removed from the list.  New messages are added whenever the conditions warrant. Most messages relate to civil geometry, superelevation, and corridor modeling.

Civil Template

A civil design concept used most often for corridor modeling but also has other applications.  The Civil Template defines the cross-sectional shape of the object being modeled.  This cross-section is then “extruded along” a 3D geometry element to form the final model. The corridor template can create or target features such as road edges.  The result is the creation of a corridor.

Clipping Reference

Clipping allows you to remove areas of overlap when working with multiple corridors in a single surface.  For example, in a corridor intersected by a crossing roadway, clipping would be used to remove all overlapped features within the intersection.

Complex Terrain Model

A terrain model created by merging or appending two or more terrain models.

Context Toolbox

When an element is selected, hovering over the element provide a heads-up and context sensitive toolbar which pops up at the cursor.  This toolbar provides a few of the most commonly used tools which operate on the element selected element type. The first tool in this toolbar is always Quick Properties.

Contour

A linear symbol representing points of equal elevation relative to a given datum.

Contour, Isopach

Contours of a delta terrain model which represent cut and fill values as contours, not elevations. A positive contour represents fill, while a negative contour is cut. 

Contour, Major

The primary elevation line indicating a specific elevation in a surface model. Usually major contours are drawn with a heavier line weight or using a different color. Elevation text labels are usually drawn in association with major contours.

Contour, Minor

A secondary elevation line indicating a specific elevation in a surface model. Minor contours are often drawn without special color or weight indexing and without elevation text labels.

Corridor

A civil object used for modeling a roadway and is automatically managed by the corridor modeling tools.

Cross Section Model

DGN models (extracted perpendicular to defined horizontal geometry) with special station elevation coordinates defined and other specialized capabilities such as view exaggeration. Cross section stations match the interval in the template drop when a corridor is used as the basis. When horizontal geometry is utilized, the left / right offsets and interval are user-defined.

Curve Stroking

Stroking is the process of automatically adding shots to the terrain model or corridor by interpolating new shots from the curved sections of the data. This distance is used to interpolate new shots along the curved element in corridor processing and applying linear templates. This value is used as a perpendicular minimum distance from chords generated along the arc. Chords are drawn along the arc and the perpendicular distance is measured from the middle of each chord to the arc. If this distance is larger than the Curve Stroking, the process is repeated with a shorter chord length. This process is repeated until the end of the curve is reached. The flatter the curve, the fewer number of points will be calculated. The steeper the curve, the greater number of points that will be calculated.

DDB File

GEOPAK file (Design DataBase) which contains features definitions, associated symbology and annotation settings.

Delta Terrain Model

A surface containing data derived from the difference in elevation between two terrain models or a terrain model and a plane.

Dialog

The tool settings box for the active command.  The dialog shows all available options for a command.  For most civil commands, most of the time, the dialog can be hidden and ignored since the user is given all necessary instruction and inputs by way of the cursor prompt.  The dialog is necessary for configuring command customizations.

Drape

The process of vertically projecting elements onto a surface so that the element elevations are defined by the surface.

Drape Void

A closed area of missing or obscured data where the void coordinates are not included in the triangulation. Voids are inserted post triangulation. The void coordinates and lines are draped on the TIN surface. Even though a user must provide an elevation for the Drape Void vertices, the user elevations are changed to the elevation of the TIN surface at the XY Drape Void coordinate position.

Element Template

MicroStation concept which allows preconfigured definitions for symbology and other miscellaneous display of MicroStation elements and civil features.

End Condition

A specialized component of a corridor template which provides information tie into active surface.

End Condition Exception

Used to modify the behavior of an end condition solution without requiring the use of additional template drops.  When an end condition exception is added, it must be edited to change its behavior.

Export to Native

Option to automatically or manually push horizontal and vertical geometry into native products (InRoads - ALG, MX - PSS and GEOPAK - GPK). 

Feature

A Feature is anything that can be seen or located and is a physical part of your design, representing a real world thing.   A feature’s definition is one of its properties.  At any given time in the design process, the feature will have a Horizontal Geometry, a Vertical Geometry, 3D Geometry or a combination to define its location.

Feature Definition

Used to define options when creating features.  These are the items which are created in advance, usually used across multiple projects and define symbology, annotation and quantities.  The feature definition is assigned (usually) in the plan model and profile/3D feature definitions follow from there.

Feature Name

Each Feature can have a name.

Gap

When a feature is trimmed the part(s) which are invisible on the base geometry.

GPK

A legacy (proprietary) GEOPAK database containing coordinate geometry information.

Graphical Filter

Using in developing terrain models, an automated way of storing search settings for graphic elements when creating terrain models using 3D element. A graphical filter can be created for each feature (i.e., spots, breaks, voids) then the filters can be defined as a Graphical filter group. 

Heads Up  Prompt

Command instructions are given in a heads up and dynamic prompt which floats at the cursor.

Horizontal Geometry

The elements which define the horizontal layout of the design.  These elements are 2D elements even if the DGN model is 3D. Horizontal Geometry may be points, lines, arcs, spirals, splines or any combination in a complex element.

Interval

When a feature is trimmed the part(s) which are visible on the base geometry.

Island

Closed area used to place within a void, i.e., islands in the middle of rivers, lakes, etc.

Key Station

Additional station added to the corridor to force processing at the particular location.

LIDAR

(Light Detection And Ranging) is an optical scanning technology which scans ground and other physical features to produce a 3D model.

Linear Feature

In plan model, composed of lines, arcs, spirals, splines or combinations of these.  In profile model, composed of lines, parabola, splines or combinations of these.

Linear Stroking

Stroking is the process of automatically adding shots to the terrain model or corridor by interpolating new shots from the linear sections of the data.  Linear stroking is measured along the element.  Interpolated vertices are added whenever the distance between the vertices is greater than the linear stroking value (in master units).

Manipulators

The heads up, on-screen editing interface.  Only the most common properties are presented in manipulators.  Manipulators are in two types:  graphical and text

Overlay Vertical Adjustment

Within Corridor Model, tool used to develop a vertical geometry (based on milling and overlay parameters) and apply to the corridor.

Parametric Constraints

Used to set up constraint value overrides for specified station ranges.

Plan Model

The usual DGN model, used for laying out horizontal geometry.  Best practices will dictate that this is a 2D DGN model but 3D DGN model can be used.  This is where geometric layouts and corridor definitions are kept. The geometric layouts are not only alignments but also edges, parking, striping, sidewalks, etc.

Point  Features

Defined by a single X, Y  (Z optional) location. A point need not be a feature.  It may be defined as a non-featurized point by way of AccuDraw, Civil AccuDraw, Snap or a data point.  Non featurized points are use to control the construction of Linear Features.

Point Cloud

A set of vertices in a 3D coordinate system and these vertices are defined the by X, Y and Z coordinates. Point clouds are usually created by 3D scanners. These devices measure a large number of points on the surface of an object and output a point cloud as a data file. The point cloud represents the visible surface of the object that has been scanned or digitized.

Point Control

Used to modify the behavior of points in a template. These controls take precedence (they override) over existing constraints on the point.

Project Explorer

MicroStation's interface for browsing elements in a DGN file.  Extended by civil to accommodate specialized civil needs.

PSS File

MX file (Plans Style Set) which provides the graphical representation for the MX string features.

Reference Element

The rule for some geometry is a calculation from another element.  This other element is the reference element.

Secondary Alignment

Used to modify the direction of cross section processing.  By default, as any given station, the cross section is created orthogonal to the main alignment/feature.  If a secondary alignment exists, then that portion of the cross section which lies outside the secondary alignment will be orthogonal to the secondary alignment instead of the main alignment.

SEP File / Method

Uses the superelevation settings which originated in GEOPAK.

SMD File

GEOPAK file (Survey Manager Database) which contains survey features definitions and associated element and textual settings.

Spot Elevation

A set of X, Y, Z coordinates representing a point on the terrain model surface. There is no implied relationship between regular points.

SRL File / Method

Uses the superelevation settings which originated in MX

Superelevation Lane

The closed area defined by the superelevation tools used for the limits of transition calculations and pivoting location.

Superelevation Section

Area along a horizontal geometry element, where superelevation will be calculated. 

Target Aliasing

Used to create the desired results when working with multiple surfaces without having to edit the template from the template library.  Target aliases can also be used so that one corridor can target the solution of another corridor.

Template Drop

An area (usually defined by station limits) along a corridor to which a specific template is applied.

Template Library

A file that stores definitions for templates, generally with an ITL file extension.

Template Transition

The transition indicator occurs in the corridor between templates of differing names.

Terrain Model

A three-dimensional DGN element defined by spots, break lines, voids, holes, contours to model a surface on the earth.

Tooltips

When hovering the cursor over an element or a handle, a tooltip is shown which gives explanatory information.

Trace Slope

Upstream - The indicated path follows the steepest ascent from a user-defined point through the terrain model terminating at a high point or the edge of the terrain model.
Downstream - The indicated path follows the steepest descent from a user-defined point through the terrain model terminating at a low point or the edge of the terrain model.

Vertical Alignment

A linear feature in profile model which serves the special purpose of defining the elevations of an alignment.

Vertical Geometry

The elements which define the vertical layout of a corresponding horizontal geometry element.  These vertical elements are 2D and are stored in a profile model.

Void

Closed shape to demarcate areas of missing data or obscure areas. No point or break data located within the void area is utilized and no triangles are created inside the void areas. The Void coordinates are included in the triangulation and void lines between successive void coordinates are inserted as drape lines on the surface. Therefore, they do not change the slope or elevations of the surface.

Watershed

Defined by either a low point within the terrain model or a low edge point along the terrain model edge, it's the closed area wherein all water would drain to the low point.

XIN File

InRoads file which contains features definitions, associated styles, annotation, and other settings.