Creating 3D Content for X-Plane 101

[tkyler]

So you're ready to create some 3D content and help the x-plane world grow?  This post should give you a minimal overview enough to get curious.

All the 3D content in x-plane is of a file format we affectionately call, "object 8".  This is because the file format was first introduced in x-plane version 8.  This file format is a plain-text file that is human readable.  The file extension of this file format is  *.obj.  This is NOT to be confused with the *.obj file extension associated with "Alias Wavefront".  Many many 3D program support the Alias Wavefront *.obj format, but be aware that this is NOT the same as the native, proprietary object 8 format.  Currently, only two 3D programs will export 3D models in the object 8 format:

1.)  AC3D  (http://www.inivis.com/)

2.)  Blender 3D  (http://www.blender.org/)

The exporter for AC3D, a low cost payware 3D program,  is developed and maintained by the author of the object 8 format and can generally be considered the "official" exporter for object 8.  The exporter takes the form of a plug-in for AC3D and can be downloaded at the following:

http://www.xsquawkbox.net/scenery/tools.php

The exporter for blender, developed voluntarily by Jonathan Harris, takes the form a series of python scripts but comes with an installer that easily places all the files for you.  The exporter scripts for blender can be downloaded at the following:

http://marginal.org.uk/x-planescenery/

3D content can be created in other 3D programs, but you'll have to get your 3D content into one of these two programs to be able to export it to object 8 for x-plane.  Blender is free and the more powerful of the two programs and the highest quality work is usually done by Blender users rather than AC3D users; however, this is not to say AC3D can't produce good work.  Blender has more robust modeling and organizational tools that allow a modeler to be a bit more productive and produce more complicated projects.  The trade off is that Blender takes a while to learn and the user interface is unintuitive.  The reason the program has popularity is because once the interface is learned, it is an extremely fast 3D program to use.

Animations are also performed in AC3D and Blender.  The animation structure for object 8 format is proprietary and animation mechanisms in other programs are not transferable to Blender or AC3D.  For users who prefer to use other 3D programs, their workflow will mostly likely consists of all steps short of animating...either modelling only or modeling and texturing and then moving the work to blender / AC3D for animating before export.

The object 8 format allows one texture per one exportable object, with UV coordinate mapping.  The one texture needs to have width and height pixel dimensions that are powers of 2, i.e. (2, 4, 8, 16......2048)  and any one dimension, width or height, cannot be larger than 2048 pixels.  The end “product” you will use within x-plane will consist of an object file and it's associated texture.

3D object files that are to be  used with aircraft are generally placed in specific locations within the aircraft folder and 3D object files to be used for scenery are generally placed in a specific folder used for scenery.  For aircraft, these 3D objects are applied to the aircraft using the “Plane-Maker” application that comes with x-plane.  For scenery, the 3D objects are added to the x-plane world in a couple of ways.  The most preferable way is by using a 3rd party application called “overlay editor” by Jonathan Harris.  This application can be found at the following:

http://marginal.org.uk/x-planescenery/tools.html

Another more painful way is to convert the binary file that contains the object placement information into a text file and hand edit the text file with the placement information (latititude, lontitude & azimuth) then reconvert that text file back to binary. 

So why would you want to take the more painful route?  Well simply put, “overlay editor” is 3rd party and Laminar Research can not count on 3rd party solutions so they must develop their own.  Laminar has a WYSIWYG scenery editor about 95% complete called “WED” that will be used for placing objects into x-plane graphically.  This “WED” application is available now for creating airports, runways and taxiways, lights, markings, etc, but does NOT currently allow the placement of 3D objects.

The “units” for object 8 format is meters, so a value of 1.0 in a 3D program would equal one meter in x-plane.

Thus far, the descriptions I've given are of a very general nature on how 3D objects are created and exported to object 8 format for x-plane to be able to use as well as how they are brought into x-plane.  What I have not gone over is the intricacies of animating objects from within AC3D and/or Blender.  I also have not covered the specifics of folder structure and exactly where to put your objects and/or how to name them, though this will be necessary to get your objects in to x-plane.  Custom scenery creation involves a few more specialized topics regarding custom texturing of the landscape as well as controlling the placement of trees, forest, roads, etc.  This post does was not intended to cover these topics in depth.

So to recap, the general procedure for getting some 3D content into x-plane is as follows:

FOR AIRCRAFT:

1.)Create your 3D content, in any 3D program you choose and texture it there if you want.

2.)Get your 3D content in to Blender or AC3D and texture it if you haven't already.

3.)Animate your objects (note that animations are associated with x-plane variables called “datarefs”)

4.)Export your object to object 8 format.

5.)Place your object and texture in the proper folder within your aircraft folder hierarchy

6.)Open the “Plane-Maker” application and add the object to your aircraft and save.

FOR SCENERY OBJECTS:

    See steps 1 - 4

5.)Acquire “Overlay Editor” application and place your objects with it.

This posting was intended to give you a broad overview of creating custom 3D objects and the generalized procedure for getting them into x-plane.  More specific posts will follow covering the process in more detail in the future.

[Daveduck]

Don't forget the far easier to learn, and quite capable (see Heron Island, Mont Blanc Tunnel packages  ) and free "SketchUp" 3D authoring program from Google.

There's also an XP import/export plug-in for it maintained by Jonathan "Marginal" Harris.

Cheers.

[tkyler]

There's also an XP import/export plug-in for it maintained by Jonathan "Marginal" Harris.

Man that guy is something else.  I didn't know that...thanks Dave.

[Daveduck]

Man that guy is something else.  I didn't know that...thanks Dave.

Yes, he is.

I was in a rush before and forgot to add the link:

http://marginal.org.uk/x-planescenery/tools.html

"SketchUp2XPlane"