Answered at FS Developer.

Briefly, to recapitulate...

The "root node" is like the root of any disk... it is the lowest level folder...

All aircraft models must have either "exterior" or "interior" as the top, or "root" node name. All other objects in the scene are Linked to that node.

Code:

exterior
   engine
   fuselage
   wings
   etc.
 

Basically you have to set a link hierarchy for all your parts... to define which are attached to which (as in, ailerons attached to wings, and other parent/child relations such as that)

Cheers

Fr. Bill wrote on Apr 7^th, 2009 at 1:48pm:


Yeah, I'm a person without discipline and order , and I'm planing to release a bit later after fsx release the two citations in FS9-sdk ,Of course I have a bigger problem about the gauges 
I'll post something about it

i would link that fuselage part to a dummy (call it exterior), so the dummy is the top node... this way, you can put the dummy at position 0, 0, 0 and move the aircraft about if you need to

makes for greater flexibility  

Cheers

Can you explain more how to set up a dummy part?

Fr. Bill wrote on Apr 12^th, 2009 at 11:31am:


For this purposes, then will it suffice for the dummy object to have only two points (therefore no polygon to even be remotely visible) or MUST it have at least one 3-point face?


(Note - Rhetorical question, for discussion, since I have the habit of making a very small hidden "cube"  as any dummy object I may need)

So I actually name the part 'Dummy' then?  I did that the named the fuselage 'exterior' and the cockpit tub (wich is at the top of that hierarchy) as 'interior'

I think what's confusing me is this:

First, how do you do the process of creating a dummy part?

and

What is the difference between have a plane (or triangle) as a dummy part and having the actual fuselage as one?  No matter how many polys they have, or how big they are (Horton Hears a Polygon?) a part is just a part...

Kevin

A dummy part is merely an anchor, like Fr. Bill says.

Think of it as the tab divider in a school kid's binder - you don't want a "regular"  page to be the divider between subjects.

Yep! That's the "Dummy" object...

...however (I can hear you groaning!), I tend to avoid using them for the most part because...

...in an FS9 compiled model, animations are stripped out of the export stream if any have been applied to a true "Dummy" object.

Rather than run the risk of such occurring, it is my practice to use only a pseudo-dummy object that I create myself.

That pseudo-dummy object being a single, tiny, square polygon who's face is downward, so it won't ever be seen.

Wing Nut wrote on Apr 15^th, 2009 at 2:06pm:


One word: consistency!

As I've stated previously, the entire model "inherits" the properties of the "root node."

One critical property is the precise location of the "root node's" axis, which must be the scene's centerpoint (0,0,0).  Another critical property is the orientation of the object's axis in the scene's world space; i.e. which "directions" the x, y and z axes point

Think of the "root node" as if it were the keystone of an arch.

All other stones in an arch must have a precise spatial relationship with the "keystone" otherwise the arch cannot be self-supporting; it will collapse as soon as the scaffolding is removed.

In a similar fashion, if you move the "root node" in the scene, every object Linked to it will move in precise formation...

If you rotate the "root node's" axes with the Gizmo and "Affect Pivot Only" selected, you simultaneously affect the pivot point orientation of every object Linked to the "root node."

These two concepts are why I choose to use a very simple object for my "root node(s)" because it's far easier to visualize the centerpoint of a single square polygon (two equilateral triangles) than it is a complex set of polygons such as a fuselage.

Remember always that it is the pivot point of an object that's the important and crucial determiner, not the object itself!