Subassembly Composer Autocad Civil 3d Tutorial Pdf

Subassembly Composer AutoCAD Civil 3D Tutorial — PDF Overview

Launching Subassembly Composer

• Windows Start Menu > Autodesk > Subassembly Composer [Year].
• Do not open it from within Civil 3D. It is a separate application.

Once opened, you will see:

• Toolbox (Left): Packets, Shapes, Geometry, Workflow, API.
• Preview (Center): A blank grid representing the assembly insertion point (origin).
• Properties (Right): For setting parameters.
• Flowchart (Bottom): For logic sequences.

Key Capabilities:

• Conditional Logic: Create "If-Then-Else" rules (e.g., If cut depth > 2m, add a bench, else add a standard slope).
• API Access: Link to surface elevations, alignment geometry, or superelevation data.
• Complex Shapes: Build retaining walls, multi-lane highways, or transit corridors with variable widths.
• Parameterization: Create input parameters (like lane width or slope ratio) that users can adjust in Civil 3D.

Why SAC is Essential:

• Dynamic behavior: Subassemblies react to superelevation, widening, and targeting (e.g., a ditch bottom targeting a surface).
• Reusability: Build it once, reuse across 100 miles of roadway.
• Precision: Add custom slope logic (e.g., "If cut depth > 5 ft, flatten backslope to 4:1").

Without a guide, the mapping between Visual Basic expressions and Civil 3D geometry is confusing. A PDF tutorial solves this by providing screenshot-based walkthroughs. Subassembly Composer Autocad Civil 3d Tutorial Pdf

Step 2: Define Input Parameters

Navigate to the Input/Output Parameters tab. Add the following Input parameters: | Name | Type | Default Value | Description | | :--- | :--- | :--- | :--- | | Width_Gutter | Double | 2.0 | Width of gutter pan (ft) | | Height_Curb | Double | 0.5 | Vertical height of curb (ft) | | Slope_Gutter | Double | -0.02 | Cross slope of gutter (ft/ft) | Subassembly Composer AutoCAD Civil 3D Tutorial — PDF

Step 6: Export and Test

• Press F7 to export the .pkt file (e.g., MyCurbAndGutter.pkt).
• In Civil 3D, open Tool Palettes > Import.
• Use the subassembly in an Assembly.
• Build a corridor, change the Width_Gutter parameter, and rebuild. The curb should expand/contract.

🧰 Quick Sample Code (SAC VB Script) – Lane Slope Calculation

If SlopeDirection = "Left" Then
    LaneSlope = -1 * LanePercentSlope / 100
Else
    LaneSlope = LanePercentSlope / 100
End If
P1 = Point(Math.PI/2, LaneSlope, LaneWidth)
L1 = Link(P1, P2, "Paved")
 Windows Start Menu > Autodesk > Subassembly Composer

This is the kind of logic a full PDF tutorial explains in detail.