Create a new Box in the MAX software.

To convert the Box into an editable polygon, you can directly right-click and select "Convert to Editable Polygon", or you can select "Edit Polygon" in the modifier.

Copy a new Box and attach the two Boxes: with one of the Boxes in the editable polygon state, click "Attach" in the panel, and then select the other Box.

The first type: overlap of two points, for example: overlap point 1 and point 2, so that the two boxes are side by side and the intersection points overlap.

Open the snapping tool, right-click the snapping tool to set the snapping options, select "Grid Points", "Vertex", and select "Start Axis Constraints" in the options. Select Box2 at the "Element" level of the edit polygon, click on the coordinate axis, when all three axes turn yellow upward, place the mouse on point 1, and the mouse will change into a cross. At this time, drag the point Move to point 2, and point 1 and point 2 of the two boxes will overlap, and there will be no gap between the two boxes.

Second type: Alignment method on two single axes. For example: Align the Y axis of point 1 with point 2.

In the same way, open the capture tool, select Box2 at the "Element" level, and click on the Y axis of the coordinate axis to make the Y axis turn yellow. Place the mouse on point 1, and the mouse will change into a cross shape. At this time, drag the point to point 2, and the Y-axis values ​​of point 1 and point 2 will be the same.

In addition, you can also try the X-axis and Z-axis alignment methods.