Autodesk provides the official Subassembly Composer Help which can be printed as a PDF.
The Subassembly Composer (SAC) is an extension included with Civil 3D that allows users to create custom lane, shoulder, and sidewalk assemblies that cannot be created with the standard Civil 3D subassembly tools. Unlike standard subassemblies, SAC allows for complex geometric logic, decision trees (If/Then scenarios), and custom output coding. This guide outlines the fundamental workflow, the programming logic structure, and a step-by-step example of creating a custom parametric shoulder. Subassembly Composer Autocad Civil 3d Tutorial Pdf
Here is a table of contents from a typical 50–80 page Subassembly Composer tutorial PDF: Here is a table of contents from a
| Chapter | Title | Key Topics | |---------|-------|-------------| | 1 | Introduction | What is SAC? Why use it? Difference from stock subassemblies. | | 2 | Interface Overview | Toolbox, Workspace, Properties, Preview pane. | | 3 | Basic Workflow | Create new PKT → Define inputs → Build geometry → Test → Export to Civil 3D. | | 4 | Parameters | Input, Output, Target parameters (Surface, Offset, Slope). | | 5 | Visual Basic Script | Simple math, conditional logic (If/Then), variables. | | 6 | Geometry Construction | Point, Link, Shape creation. Sequences and loops. | | 7 | Conditional Subassemblies | Decision making (Pavement structure vs. trench). | | 8 | Advanced Targets | Lane widening, daylight to multiple surfaces. | | 9 | Superelevation & Cant | Applying superelevation to custom lanes/shoulders. | | 10 | Event Viewer & Debugging | Validating PKT, common errors. | | 11 | Testing in Civil 3D | Import PKT, assembly creation, corridor preview. | | 12 | Real-World Examples | Urban curb & gutter, rural ditch, retaining wall. | Target parameters (Surface