Tutorial_4(en US)

Knowledge points:

• Start object belongs to start object/parent object/, Next object belongs to child object
• Drag and drop Next object, the default action is to insert
• When dragging and dropping Next while holding down Left Alt, this action will become adding from the end.
• If the position (TGrid) of the child node is lower than its previous node, then it belongs to an illegal line segment, and the line segment it belongs to will become a dotted line.