Preselection helps you select reference geometry or Sketcher objects, such as lines, vertices, and dimensions. When preselection is enabled and you move the cursor near one of these objects, ABAQUS/CAE highlights the object so that you can more easily select it. Preselection also helps constrain your sketch by indicating selections that will create horizontal, vertical, colinear, perpendicular, and coincident constraints while you sketch. For a list of the preselection symbols displayed by different Sketcher objects as you move the cursor around the sketch, see “The Sketcher cursors and preselection,” Section 19.4.5.
Toggle Preselect geometry in the Sketcher Options dialog box to enable or disable preselection. (By default, preselection is enabled when you start the Sketcher.) Preselect customization is stored for the duration of the ABAQUS/CAE session and applies to all sketches. Preselection overrides snapping to the grid if a preselection point and a grid point are both close to the cursor position.
To turn preselection on or off:
From the bottom of the Sketcher toolbox, select the Sketcher customization tool 
.
The Sketcher Options dialog box appears.
From the General tabbed page, toggle Preselect geometry.
When Preselect geometry is on, ABAQUS/CAE highlights valid selections, such as vertices, midpoints, and dimensions, as you move around the sketch.
When Preselect geometry is off, ABAQUS/CAE does not highlight valid selections.
After you have chosen the desired customization options, click OK to apply your changes and to close the Sketcher Options dialog box.
