Parent Tool
From K-3D
The 
Parent Tool is used to "parent" nodes together.
- Clicking on unselected node replaces the current selection with that node.
- Clicking on a selected node starts the parent action. The mouse cursor changes
to indicate that the next node selected will become the parent of the currently-selected nodes.
- All selected nodes are parented to the next node clicked on, which ends the parent action.
The Parent Tool and the Unparent Command adjust a child's transform history to compensate for any parent transformations. Put another way, when you parent / unparent a child object, it retains its position / orientation / scale, relative to its parent.
