Appendix E: Making Objects for X-Plane

A common question for customer support is, "I want to model objects for X-Plane—what formats do you use?”.

There are a few parts to that answer.

First of all, for the aircraft itself, there is only one answer—the X-Plane .acf file, as saved by Plane-Maker (bundled with the simulator and located in the X-Plane 9 directory). X-Plane looks at this file to determine flight physics, mass properties, engine power and limits… the works. As such, it is highly customized to X-Plane and could never be any sort of “all-purpose" format. This means that you can only use Plane-Maker, and nothing but Plane-Maker, to make the aircraft.

While Plane-Maker is perfectly adequate for entering the design of the plane (it is bug-free, easy to use, not too fancy, and reliable) Plane-Maker is not a 3-D model editor. Instead, it is used to lay out the basic aerodynamic shapes and properties which result in an airplane that looks okay, but would certainly not knock anyone’s socks off. As such, it can not make the complex 3-D model that is needed to make a cool 3-D cockpit, or to make a highly detailed aircraft model that might overlay the basic Plane-Maker model from which flight physics are calculated.

These 3-D models can also be used to create buildings and other custom objects—not just plane overlays and cockpits.

So, to repeat:


 * 1. Plane-Maker can be used on its own to make a model for X-Plane. It will look okay and will fly fine.  It will be pretty good.


 * 2. In addition to this Plane-Maker model, you can make a 3-D cockpit to sit inside the plane, or a highly detailed aircraft model to overly the basic X-Plane model, which could actually be made with transparent textures to be invisible, if you desire.

Clearly, users can use Plane-Maker, which comes with X-Plane, to do part 1 above, but not part 2.

See the "Example Aircraft" in the "Instructions" folder for a very simple example.

So, what editor does one use for part 2?

To do part 2 of the above, you will need a 3-D editor capable of saving an object in the X-Plane OBJ format. Note: This is not the same as the Alias OBJ format.

The following file formats can be used to create X-Plane OBJ files:
 * 3DS (Autodesk 3D Studio)
 * DXF (Autocad)
 * OBJ (Alias Wavefront)
 * AC (AC3D)
 * MD2 (Quake model)
 * WRL (VRML)
 * LWO (LightWave)
 * TXT (Milkshape)

With each of these file extensions, users need to convert the objects to ones usable by X-Plane. This is often done by opening the file in AC3D, then using the X-Plane plugin downloadable here to export the file as an X-Plane OBJ.

Alternatively, after an object has been created in 3DS or Autocad, ObjConverter may to be used to convert it. ObjConverter comes in the Scenery Tools pack, downloadable here.

Alternatively, direct export to an X-Plane OBJ file is available in the two free 3-D editors by Jonathan Harris—both Google Sketchup and Blender.

Note: All of these exports are limited by file format issues:
 * 3DS doesn't feature lines, only meshes.
 * DXF/Autocad has no texturing info.
 * Lightwave's texturing model doesn't correspond to ours very well.
 * VRML conversion between programs doesn't usually work well.

There may be other issues, too, in converting between formats.

In all cases, though, the file needs one texture per object.

The bottom line is that there are a lot of ways to get objects into X-Plane from just about any 3-D editor imaginable. If it isn't on this list, and the 3-D editor is decent, it can probably export to one of these formats such as 3DS, Alias Waverfront OBJ, or similar.

For pure "meshes" made with one texture, no tricks, 3DS seems to be the most reliable conversion format for simple work.