By default, all joints
Joints drawn in the same location within the graphical interface will get merged automatically. The significance of a Special Joint is that it is not automatically deleted by the graphic interface if (or when) no objects are connected to it. If a joint is not designated as a special joint, then the graphic interface will always delete it if it is not connected to an object.You can create multiple joints in the same location by using one of the following approach:
...
are automatically merged, and joints not connected to a structural object are automatically deleted. Under these circumstances, special joints are not merged or deleted.
Special joints may be created such that they coincide with another joint location through one of the following methods:
- Disconnect the joints