Adding, deleting and middle line 2
With the ZSphere loaded, Draw (Q) will be enabled and you can simply click the ZSphere and drag to create another ZSphere. To delete a ZSphere, hold Alt and click it. With Symmetry turned On, hover over the centre of the ZSphere and you’ll see that the two red dots snap into a single green one. This will create a new ZSphere in the middle.
With symmetry turned on you’ll see a small dot that mirrors the placement of your active (red) ZSphere. You can also choose the ZSphere from the Tool palette. Load any project or tool from the lightbox with a double-click. You can move a ZSphere constrained to the middle line with Symmetry turned on. The cursor will snap to a green dot to indicate the middle line.