Link molecules to other objects.
Hierarchy
Molecules can be linked to objects above or below, in the Gamgi 
hierarchy. Pressing the button 
Below (the default), the 
Objects menu shows the classes of objects that can be owned 
by molecules: Group, Plane, Direction, Atom (the default), Orbital 
and Text. Pressing the button 
Above, the same menu shows 
the classes of objects that can own molecules: Layer (the default), 
Assembly, Cell and Cluster. 
Object
Gamgi expects users to identify first the molecule or list of molecules
and then the object to link. When the 
Molecule entry is active
and empty, clicking the mouse over a molecule, on the current layer
(local selection), its identification is transported to the 
Molecule
entry. Gamgi is now expecting users to click on a object of the 
class currently selected in the 
Object menu. This object 
can be in a different layer or even in a different window (global 
selection). 
To select a visible object in a different layer, in the same window, 
just press the mouse over the object, as if it was in the current 
layer. To select objects without visual representation, as layers
and lights, press the mouse over the graphic area in the window,
to create a menu with all the objects of that class in the window, 
which can then be selected. To select an object in a different window, 
with the mouse, use exactly the same procedure, in that window.
Link
Gamgi suppports only one type of linking mode for Molecule: 
Object.
The 
Object method links a molecule to a single 
Object. 
When the 
Hierarchy is 
Above, the molecule is unlinked 
from its current parent and linked to the object. When the molecule 
is moved to a different layer, all its bonds to other objects are 
automatically removed. When the 
Hierarchy is 
Below, 
the object is unlinked from its current parent and linked to the 
molecule. An error is issued when the parent already owned the 
child object. 
After the linking operation, Gamgi always puts on top
the window and layer containing the linked objects.