Autodesk Subassembly Composer (SAC) is a powerful authoring tool used to create custom subassemblies for Civil 3D corridors without requiring advanced programming. While Civil 3D includes a vast library of stock subassemblies, SAC allows you to design complex, rule-based cross-sections tailored to specific project requirements.

Displays a real-time visualization of the geometry as you build it.

The workspace where you drag and drop components to build the logic of your subassembly.