Box selection is the process of holding down the left mouse button and dragging a rectangular area to select objects. Click and box selection do not require any input parameters, and are undoubtedly the most convenient and commonly used selection methods in CAD. In order to fully utilize box selection, CAD corresponds to the two selected options: window mode (Window) and crossing mode (Crossing) from right to left and left to right box selection.

In CAD, selecting a box from left to right is a window mode, and all vertices and boundaries of the shape are selected only when they are completely within the rectangular box range; The right to left box selection is a cross mode, and any vertex and boundary within the rectangular box selection range of the shape will be selected.

Window selection and cross selection are suitable for different situations. The advantage of window selection is that it can avoid accidentally selecting surrounding graphics, while the advantage of cross selection is that it only needs to pull a small selection box to select graphics.