Adding 3D Elements Over 2D AutoCAD

Any referenced datasets can be downloaded from "Module downloads" in the module overview.

Add 3D Walls to a 2D Underlay - Exercise

As I have mentioned several times, there is no actual 2D to 3D conversion. Rather, we use the information in the underlay, be it CAD, PDF, or scanned images, as a guide to build our BIM model.

To start modeling walls on top of a CAD link, use the following steps:

  1. Open your Revit project, if not already open.
  2. Go to your Level 1 CAD Background view.
  3. Zoom in to the area around the B/1 grid intersection.
  4. Toggle on Thin Lines (through the Quick Access toolbar or using the TL keyboard shortcut).
  5. Dimension the two AutoCAD lines that represent a wall, as shown below. It is a 10" wall.



  6. In the Architecture tab>Build panel, click Wall.
  7. In the Type Selector, select the Generic - 8" wall and click Edit Type.
  8. In the Type Properties dialog box, click Duplicate…. Change the name to Exterior - Generic 10" and click OK.
  9. Click the Edit… button for the Structure, and in the Edit Assembly dialog box, change the Thickness to 10", as shown below.



  10. Click OK to close the Edit Assembly dialog box.
  11. Review the properties of the newly created wall type, as shown below, then click OK.



  12. In the Options Bar, change the Location Line to Finish Face: Exterior.
  13. Trace the exterior walls, starting in the direction shown below.



    • Keep checking the wall widths as you go. If the width changes, change the wall type to suit the width. First check to see if a wall type exists; if not, create one as done previously.
    • When the endpoints of the walls are not obvious, project beyond the walls and start another wall, then you can clean up the intersections/corners later with the Trim and Extend commands.
    • In order to see the CAD lines underneath the Revit walls, change the visual style to Wireframe, as shown below.



    • If unsure what a CAD line represents, use the Query tool to see what layer it is on, as shown below.



  14. Move on to the interior walls. Select the Interior – 4 7/8" Partition wall type, as shown below.



  15. Change the Location Line to Finish Face: Interior.
  16. Create the interior walls.
    • If your wall is being created on the wrong side, press <Space bar> to toggle which side the wall is on.
  17. Repeat this for the entire floor plan, adding walls as you go. Once you finish, you can start building the wall types and add doors and windows.
  18. Flip to a 3D view to check your progress, as shown below.