Alignments

Components for reading, inspecting, and creating Civil 3D alignments together with their geometry, properties, and design information.

CVL-AlignAlignments

Civil3d Alignment

Civil3d › Alignments · Introduced v1.1.19

Extracts information from a Civil 3D Alignment. Feed it an alignment and it breaks out the alignment's identity, its grouped properties, its individual geometry entities, the centerline as a Rhino curve, and any associated labels. Use it as the starting point for inspecting or further processing an existing alignment.

Inputs

AlignmentCivil3d Alignment

A Civil3d Alignment

Outputs

IdAutoCAD ObjectId

The Id of the Alignment.

PropertiesCivil3d Alignment Properties

Alignment properties (use Alignment Properties component to extract values).

EntitiesCivil3d Alignment Entity

The individual entities (Lines, Arcs, Spirals) of the Alignment.

CurveCurve

The alignment centerline as a Rhino curve.

Label GroupsCivil3d Alignment Label Group

Auto-generated label groups from the Alignment.

LabelsCivil3d Feature Label

Individual labels from the Alignment.

Exceptions

Level	Message	Cause & fix
Error	No document available	The drawing that owns the alignment could not be found. Make sure the source document is open.
Error	Failed to read Alignment	The alignment could not be read from the drawing. Confirm the input still references a valid alignment.

Civil3d Alignment Entity

Civil3d › Alignments · Introduced v1.1.19

Extracts individual values from a Civil 3D Alignment Entity. An alignment is made up of a sequence of entities (lines, arcs, spirals); this node reports a single entity's type, its station range, length, position index, geometry, and the sub-entities that compose it. Use it after the Civil3d Alignment node to inspect each piece of an alignment in turn.

Inputs

EntityCivil3d Alignment Entity

An alignment entity from a Civil3d Alignment

Outputs

TypeText

The type of entity (Line, Arc, Spiral, etc.).

Start StationNumber

The starting station of this entity along the alignment.

End StationNumber

The ending station of this entity along the alignment.

LengthNumber

The length of this entity.

IndexInteger

The index of this entity in the alignment.

CurveCurve

The entity geometry as a Rhino curve.

Sub-EntitiesCivil3d Alignment Sub-Entity

The sub-entities that make up this alignment entity.

Civil3d Alignment Properties

Civil3d › Alignments · Introduced v1.1.19

Extracts individual values from Civil 3D Alignment Properties, including name, description, station range, length, type, and links to the site, style, and design check set. It can also write changes back: supplying a new Name or Description updates the alignment in the drawing. The richer property groups (reference station, design speeds, CANT, and connected/offset/rail info) are passed out for the dedicated Info nodes to unpack.

Inputs

PropertiesCivil3d Alignment Properties

Alignment properties from a Civil3d Alignment

NameTextoptional

The name of the alignment. When set this will update the name of the alignment.

DescriptionTextoptional

The description of the alignment. When set this will update the description of the alignment

Outputs

NameText

The name of the alignment.

DescriptionText

The description of the alignment.

Start StationNumber

The starting station of the alignment.

End StationNumber

The ending station of the alignment.

LengthNumber

The total length of the alignment.

Alignment TypeText

The type of alignment (Centerline, Offset, CurbReturn, etc.).

SiteNamed Id

The site containing this alignment as a NamedId.

StyleNamed Id

The style applied to this alignment as a NamedId.

Design Check SetNamed Id

The design check set applied to this alignment as a NamedId.

Reference StationCivil3d Reference Station

The reference station information.

Design SpeedsCivil3d Design Speeds

The design speed information.

CANT InfoCivil3d CANT Info

The CANT (superelevation) information.

Connected Alignment InfoCivil3d Connected Alignment Info

The connected alignment information.

Offset Alignment InfoCivil3d Offset Alignment Info

The offset alignment information.

Rail Alignment InfoCivil3d Rail Alignment Info

The rail alignment information.

Exceptions

Level	Message	Cause & fix
Error	No document available	The drawing that owns the alignment could not be found. Make sure the source document is open.

Civil3d Alignment Sub-Entity

Civil3d › Alignments · Introduced v1.1.19

Extracts individual values from a Civil 3D Alignment Sub-Entity. Some alignment entities (such as compound spiral-curve-spiral groups) are themselves built from smaller pieces; this node reports a single sub-entity's type, station range, length, index within its parent, and geometry. Use it after the Civil3d Alignment Entity node to drill into the finest level of alignment geometry.

Inputs

Sub-EntityCivil3d Alignment Sub-Entity

A sub-entity from a Civil3d Alignment Entity

Outputs

TypeText

The type of sub-entity (Line, Arc, Spiral).

Start StationNumber

The starting station of this sub-entity along the alignment.

End StationNumber

The ending station of this sub-entity along the alignment.

LengthNumber

The length of this sub-entity.

IndexInteger

The index of this sub-entity within its parent entity.

CurveCurve

The sub-entity geometry as a Rhino curve.

Civil3d CANT Info

Civil3d › Alignments · Introduced v1.1.19

Extracts values from Civil 3D Alignment CANT (superelevation) information. CANT describes how a rail alignment is banked through curves; this node reports whether CANT data exists and lists the critical stations, their CANT values, and the start and end stations of the CANT curves. Feed it the CANT Info output of the Civil3d Alignment Properties node.

Inputs

CANT InfoCivil3d CANT Info

CANT information from a Civil3d Alignment

Outputs

Has CANTBoolean

Whether the alignment has CANT data.

Critical StationsNumber

Station values of CANT critical points.

Critical CANT ValuesNumber

CANT values at critical stations.

Curve Start StationsNumber

Start stations of CANT curves.

Curve End StationsNumber

End stations of CANT curves.

Civil3d Connected Alignment Info

Civil3d › Alignments · Introduced v1.1.19

Extracts values from Civil 3D connected alignment information. A connected alignment ties two parent alignments together; this node reports whether the alignment is connected, the overlap lengths and offsets at the incoming and outgoing ends, and the ObjectIds of the incoming and outgoing parent alignments. Feed it the Connected Alignment Info output of the Civil3d Alignment Properties node.

Inputs

Connected InfoCivil3d Connected Alignment Info

Connected alignment information from a Civil3d Alignment

Outputs

Is Connected AlignmentBoolean

Whether this is a connected alignment.

Connection Overlap Length InNumber

The connection overlap length at the incoming end.

Connection Overlap Length OutNumber

The connection overlap length at the outgoing end.

Incoming Parent Alignment IdAutoCAD ObjectId

The incoming parent alignment ObjectId.

Outgoing Parent Alignment IdAutoCAD ObjectId

The outgoing parent alignment ObjectId.

Offset InNumber

The offset value at the incoming connection.

Offset OutNumber

The offset value at the outgoing connection.

Civil3d Design Speeds Info

Civil3d › Alignments · Introduced v1.1.19

Extracts values from Civil 3D Alignment design speed information. Design speeds are defined at stations along the alignment; this node returns the paired lists of stations and the speed applied from each. Feed it the Design Speeds output of the Civil3d Alignment Properties node.

Inputs

Design SpeedsCivil3d Design Speeds

Design speed information from a Civil3d Alignment

Outputs

StationsNumber

Station values for speed changes.

SpeedsNumber

Speed values at each station.

Civil3d Offset Alignment Info

Civil3d › Alignments · Introduced v1.1.19

Extracts values from Civil 3D offset alignment information. An offset alignment runs parallel to a parent alignment; this node reports whether the alignment is an offset, its nominal offset distance and side, the parent alignment's ObjectId, and the start/end stations and offset values of each offset region. Feed it the Offset Alignment Info output of the Civil3d Alignment Properties node.

Inputs

Offset InfoCivil3d Offset Alignment Info

Offset alignment information from a Civil3d Alignment

Outputs

Is Offset AlignmentBoolean

Whether this is an offset alignment.

Nominal OffsetNumber

The nominal offset distance from the parent alignment.

SideText

The side of the offset (Left or Right).

Parent Alignment IdAutoCAD ObjectId

The parent alignment ObjectId.

Region Start StationsNumber

Start stations of offset regions.

Region End StationsNumber

End stations of offset regions.

Region OffsetsNumber

Offset values of regions.

Civil3d Rail Alignment Info

Civil3d › Alignments · Introduced v1.1.19

Extracts values from Civil 3D rail alignment information. This node reports whether the alignment is a rail alignment and, if so, its track width (rail gauge). Feed it the Rail Alignment Info output of the Civil3d Alignment Properties node.

Inputs

Rail InfoCivil3d Rail Alignment Info

Rail alignment information from a Civil3d Alignment

Outputs

Is Rail AlignmentBoolean

Whether this is a rail alignment.

TrackWidthNumber

The rail gauge value.

Civil3d Reference Station

Civil3d › Alignments · Introduced v1.1.19

Extracts values from Civil 3D Alignment reference station information. The reference station ties a known point to a known station value, anchoring the alignment's stationing. This node reports whether a reference point exists, its world-coordinate location, and the station value at that point. Feed it the Reference Station output of the Civil3d Alignment Properties node.

Inputs

Reference StationCivil3d Reference Station

Reference station information from a Civil3d Alignment

Outputs

Has Reference PointBoolean

Whether the alignment has a reference point.

Reference PointPoint

The reference point location in world coordinates.

Reference Point StationNumber

The station value at the reference point.

Create Civil3d Alignment

Civil3d › Alignments · Introduced v1.1.19

Creates a Civil 3D Alignment from a Rhino curve. Provide the curve and, optionally, a name, site, layer, style, label set, and alignment type; the node draws the alignment into the target drawing and returns the new alignment, its name, and its ObjectId. If a name is not supplied a unique one is generated, and if a style or label set is omitted the document defaults are used.

Inputs

DocumentAutoCAD Documentoptional

An AutoCAD Document. If not provided, the active document will be used.

CurveCurve

The Rhino curve to create the alignment from.

NameTextoptional

The name for the Alignment. If not provided, a unique name will be auto-generated (e.g., GH_Alignment_001).

SiteCivil3d Siteoptional

The site for the alignment. If not provided, a siteless alignment will be created.

LayerAutoCAD Layeroptional

The layer for the alignment. Uses the current layer if not provided.

StyleCivil3d Alignment Styleoptional

The alignment style to apply. Can be a style name (string) or a style object. Uses Civil 3D default if not provided.

LabelSetCivil3d Alignment Label Set Styleoptional

The alignment label set style to apply. Can be a style name (string) or a style object. Uses Civil 3D default if not provided.

TypeIntegeroptional

Alignment type: 1=Centerline (default), 2=Offset, 3=CurbReturn, 4=Utility, 5=Rail

Outputs

AlignmentCivil3d Alignment

The created Alignment.

NameText

The name of the created alignment (useful when auto-generated).

IdAutoCAD ObjectId

The ObjectId of the created alignment.

Menu & behaviour

Right-click Replace Previous Object (on by default) — deletes the objects this node previously created before making new ones, so editing inputs updates the drawing in place instead of leaving duplicates behind.
Right-click Save Connection Between Sessions (on by default) — remembers the link to created objects when the Grasshopper file is saved and reopened.
Right-click Clear Connection — forgets the tracked objects without deleting them from the drawing.
Skips re-creating objects when inputs are unchanged (shows the remark "No change in inputs, reusing last created"), and defers one solve after a Rhino undo/redo to avoid a Civil 3D crash.

Exceptions

Level	Message	Cause & fix
Error	No active AutoCAD document available	No document was supplied and there is no active drawing. Open a drawing or connect a Document input.
Warning	No curve provided	The Curve input is empty. Supply the curve to build the alignment from.
Error	Invalid alignment type. Must be 1-5 (1=Centerline, 2=Offset, 3=CurbReturn, 4=Utility, 5=Rail)	The Type value is outside 1–5. Use a value in that range (the Civil3d Alignment Type value list provides valid options).
Error	Civil 3D error: {message}	Civil 3D rejected the alignment creation; the underlying message explains why.
Error	Failed to create alignment: {message}	An unexpected error occurred while creating the alignment; the message gives details.
Error	Failed to create alignment. The alignment name may already exist.	Creation returned nothing, often because an alignment of the same name already exists. Choose a different name.
Error	Failed to create alignment	The alignment could not be created for an unspecified reason. Check the inputs and try again.

Get Civil3d Alignment Styles

Civil3d › Alignments · Introduced v1.1.19

Gets all Alignment Styles from the current Civil 3D document. Use it to list the available styles so you can feed one into the Create Civil3d Alignment node, or simply to audit what styles a drawing contains. Leave the Document input empty to read from the active drawing.

Inputs

DocumentAutoCAD Documentoptional

An AutoCAD Document. If not provided, the active document will be used.

Outputs

StylesCivil3d Alignment Style

All Alignment Styles in the document.

Menu & behaviour

Recomputes automatically when relevant objects are added, modified, or erased in the AutoCAD/Civil document.

Exceptions

Level	Message	Cause & fix
Error	No active AutoCAD document available	No document was supplied and there is no active drawing. Open a drawing or connect a Document input.
Warning	No alignment styles found in the document	The drawing contains no alignment styles. This is expected for an empty drawing.

Get Civil3d Alignments

Civil3d › Alignments · Introduced v1.1.19

Gets all Alignments from the current Civil 3D document. Use it as the entry point for working with existing alignments: the output list can be filtered, then fed into the Civil3d Alignment node to extract details. Leave the Document input empty to read from the active drawing.

Inputs

DocumentAutoCAD Documentoptional

An AutoCAD Document. If not provided, the active document will be used.

Outputs

AlignmentsCivil3d Alignment

All Alignments in the current document.

Menu & behaviour

Recomputes automatically when relevant objects are added, modified, or erased in the AutoCAD/Civil document.

Exceptions

Level	Message	Cause & fix
Error	No active AutoCAD document available	No document was supplied and there is no active drawing. Open a drawing or connect a Document input.
Warning	No alignments found in the document	The drawing contains no alignments. Create one first, or check you are pointed at the right document.

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