Finding the correct set of constraints to assemble a component can sometimes be tricky, even for an experienced user. The Snap function enables you to drag a component being placed to its approximate location in the assembly. When you move the component in the assembly, a suggested placement appears as highlighted for both references as long as the pointer remains within a specific proximity. Accept the placement by releasing the component, or refuse it by dragging the component beyond the region.

When you use component interfaces or copy and paste a component in an assembly many assembly references are available for placement. The system attempts to snap to the first reference encountered. The snap_single_constraints configuration option allows you to continue moving the component to the desired location and to snap to a single constraint at a time.

By using the Snap functionality together with automatic constraint selection, you can define constraints easily. For example, when you assemble a bolt to a plate with many holes, snap and autoselection allow you to align and then mate or align the bolt to the plate with the mouse. You can select the axis of the bolt, slide it close to the axis of one of the holes on the plate, and then release the mouse button. The bolt snaps to the axis of the hole, and the constraint is established. Now that the bolt is aligned, position it for the next constraint. Select a surface on the bolt and slide the bolt along the axis of the first constraint until it is close to a reference to which it can mate or align. When you release the mouse button, the new constraint is established automatically.

The snap reference table shows how the system defines best-guess constraint types to match the selected reference with another reference.