Projecting 3D Silhouette Edges

This task shows you how to create geometry in the current design view by projecting the silhouette edge of a 3D element onto the view plane.
Open the Disk4.CATPart document. Select Start > Mechanical Design > 2D Layout for 3D Design to open the layout in the 2D window, alongside the 3D window.

Make sure the front view is active. If not, double-click to activate it. Create a right projection view from the existing front view.

In the Visualization toolbar, activate the Cutting Plane and the Display Backgrounds as Specified for Each View icons.


  1. Double-click the right view to activate it.

  2. Click the Project 3D Silhouette Edges icon in the 3D Geometry toolbar (Use-edge sub-toolbar).

  3. In the 3D background of the section view, select the canonical surface to be projected.

    The silhouette edge is projected onto the right view plane.

  4. Optionally, deactivate the Display Backgrounds as Specified for Each View icon to view the projected silhouette edge without the 3D background.

More about projecting 3D silhouette edges

When projecting 3D silhouette edges, remember the following points:

  • You can only project a silhouette edge from a canonical surface (cylinder, sphere, torus) whose axis is parallel to the view plane.
  • The projected geometry is created in the current view.
  • If the selected element is invalid, an error message is displayed.