When you sketch the profile of a feature, ABAQUS/CAE projects onto the sketch sheet the part edges and vertices that are in the same plane as the sketch plane. In addition, ABAQUS/CAE projects all datum axes and datum points onto the sketch sheet. These projected lines and points are called reference geometry, and you can use them for reference while sketching. If you want to use other edges and vertices, you must project them onto the sketch plane as reference geometry by selecting Add
References from the main menu bar. Alternatively, if you want to create new sketch edges from existing model edges, you can select AddEdges from the main menu bar (for more information, see “Projecting edges onto a sketch,” Section 19.15).
To add reference geometry:
From the Sketcher toolbox, select the Project References tool 
. For a diagram of the tools in the Sketcher toolbox, see “The Sketcher tools,” Section 19.4.1.
ABAQUS/CAE displays prompts in the prompt area to guide you through the procedure.
Select the edges and vertices you want to project into the sketch plane as reference geometry.
Click mouse button 2 to indicate you have finished selecting edges and vertices.
ABAQUS/CAE allows you to select the projection of the edges and vertices in the sketch plane.
