If you installed Civil 3D with samples:
Where you define the subassembly's name and its Input/Output Parameters , such as lane width or depth. 2. Core Geometry Building Blocks Subassemblies are built from three fundamental elements: Subassembly Composer Autocad Civil 3d Tutorial Pdf
In the "Input Parameters" panel, you set up the variables you want to control in Civil 3D. For example, if you are building a custom sidewalk, you might create parameters for SidewalkWidth and SidewalkSlope . If you installed Civil 3D with samples: Where
| 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. | For example, if you are building a custom
Autodesk provides the official Subassembly Composer Help which can be printed as a PDF.