Select the required reference plane along the width in the 3D area.
In the context toolbar, click
Set as CenterLine .
Warning:
The Set as CenterLine command is available only for the planes along the width. It will be unavailable for reference planes along the length and the height.
The selected reference plane is set as CenterLine.
Tips:
You can add other categories to the reference plane that is set to centerline. However, after you set the reference plane to centerline, you cannot change it. To change the centerline of the reference plane system, you need to set the another reference plane as CenterLine.
If you select the centerline reference plane in the tree, the corresponding plane is highlighted in the 3D area.