Corridor Creation via 3D PolyLine

Insert the PolyLine Alignment into Revit

Link or import your DWG file containing the 3D PolyLine into the Revit project. The polyline must be a true 3D PolyLine — its vertices must carry Z elevation values that represent the finished bridge profile. A flat 2D polyline will produce a corridor with no vertical curvature.

Once inserted, navigate to AutoBRIDGE → Corridor → 3D PolyLine from the ribbon to launch the interface.

Insert your 3D PolyLine as a linked or imported CAD file, then open AutoBRIDGE → Corridor → 3D PolyLine

Choose Layer & Identify the PolyLine

In the Alignment tab, open the layer dropdown and select the CAD layer that contains your 3D PolyLine. AutoBRIDGE scans the linked file and lists all polylines found on that layer. Identify the correct polyline by its total length — each entry in the list shows the polyline's measured length, which is the most reliable way to distinguish between multiple polylines on the same layer.

• Layer name — must match the layer the 3D PolyLine is drawn on in the DWG.
• Length identifier — select the polyline whose length matches your bridge centreline length.

Alignment tab — select the CAD layer then identify the correct polyline by its measured length

Assign Nested Family & Map Subcategories

Select a host Template family, then choose your Nested Family — the adaptive cross-section that gets swept along the 3D PolyLine. Map its geometry elements to the correct subcategories:

• Solid subcategory → structural and surface geometry visible in the Revit model.
• Void subcategory → internal cuts or openings within the cross-section.

Correct subcategory mapping ensures proper visibility, material assignment, and schedule behaviour in Revit views.

Family tab — select the template and nested family, then map geometry to Solid and Void subcategories

Manual Entry — Start & End Stations with Frequency

Each row in the Chainages table represents one corridor span with independent settings. Enter the Start and End station in metres for each span, and set the Frequency — the longitudinal spacing between generated adaptive cross-sections within that span.

• Start / End — chainage in metres measured along the 3D PolyLine from its starting vertex.
• Frequency — spacing in metres between adaptive instances. Smaller values produce smoother curves.

Chainages tab — enter start/end stations and frequency for each corridor span row

Lines Option — Auto-Generate Span Stations

For bridges with many spans or complex span arrangements, the Lines option automates station entry. In Revit, draw a set of transverse lines crossing the polyline alignment at each span boundary — these represent pier lines, abutments, or any structural reference. Group all the lines together using Create Group, give the group a name, then back in the Chainages tab:

1. Select the Lines option in the tab.
2. Choose the group name from the dropdown.
3. Press OK — AutoBRIDGE intersects each group line with the polyline path and automatically populates the Chainages table with a row for every span.

This is the fastest way to set up chainages when pier positions are already drawn as reference lines in the Revit model.

Lines option — AutoBRIDGE intersects the group lines with the polyline and auto-fills all span start/end stations

Section Arrangement — Optional Fine-Tuning

The Section Arrangement option controls where AutoBRIDGE anchors the adaptive instance distribution within a span. Choose the mode that best suits your project requirements:

• Start — instances begin at the span start station and progress forward. Suitable for most standard bridge spans.
• End — instances begin at the span end and progress backward.
• From Center — distribution starts at the span midpoint and works symmetrically outward. Ideal when a mid-span expansion joint must be honoured.
• To Center — instances converge from both ends toward the midpoint.

For typical workflows, leave this at the default Start setting and proceed to Run.

Settings → Corridor tab — Section Arrangement and other advanced placement controls (shared with Civil 3D method)

Click Run — Generate the Corridor

The Run button processes all span rows in sequence. For each frequency step along each span, an adaptive family instance is placed at the correct 3D position and bearing derived from the polyline geometry. Each instance is tagged with AutoBRIDGE_Type = "AutoBRIDGE_Corridor" automatically.

Run in progress — AutoBRIDGE is reading the 3D PolyLine and placing adaptive corridor instances

Success Confirmation & Result

A success dialog confirms how many adaptive instances were placed. Your corridor is now a fully parametric Revit model driven by the 3D PolyLine geometry — ready to use as the alignment source for Pier Designer, Girder Automation, and other AutoBRIDGE modules.

Success confirmation — corridor generated and visible in the Revit 3D view, fully parametric and aligned to the 3D PolyLine