Autodesk maintains a robust help file that functions perfectly as a PDF reference guide. It covers the definition of every node (geometry, auxiliary, decision) available in the software.
The canvas where you construct the logical sequence of your subassembly. Components connect sequentially to establish how Civil 3D reads and builds the geometry.
Assigned to points to generate feature lines along the corridor corridor. Standard codes include "Top" , "Crown" , "ETW" (Edge of Travelled Way), and "Subbase" .
The element acts as an IF/THEN conditional statement within your flowchart.
: Set up input/output parameters (like Lane Width or Pavement Depth) and target parameters (like a surface to daylight to). Add Geometry : Drag points, links, and shapes from the Assign Logic
Once you master basic geometry, a comprehensive will move into advanced logic:
Link subassembly elements to Civil 3D surfaces, alignments, and profiles.
Set Delta X to 0 and Delta Y to CurbHeight . Check ( L2 ). Step 4: Complete the Top and Face Geometry
Updated tutorials for the 2026 version.
The code tracks the absolute bottom of the earthwork excavation layer, which is essential for calculating bulk earthwork volumes. Shape Codes
Subassembly Composer is a standalone application that installs alongside Civil 3D. It provides a visual interface where you can build custom subassemblies from scratch using a flowchart-style logic.
