Combining Parts From One Aircraft Model to Another

I ask this question and make this post with tongue in cheek because I have never in my life created an aircraft for Flight Simulator, although I did dabble with the FSX SDK P-38 Tutorial a bit, just never could get the hang of it. I cringe as I type, because I fear I will get more "sticks and stones" than suggestions, but it never hurts to ask.

I would like to be able to take the exterior model engine parts from one aircraft and place them on a second different aircraft. Both are freeware models and before I would even attempt such a thing I would of course contact both of the original authors, describe my "project", and ask their permission before beginning. Before I do that I would like to know if it is even possible. If not, then there would be no point in making contact with the authors.

I will say this much, if possible and I get the authors' permission, I doubt I will be very successful. I've used GMAX to create hangars, light poles, and muni terminals before with good success, but straight lines and texturing is easy on "a box", probably not on a curved surface. I created a "ball" and a "cube" with Blender and went no further. It was tough to grasp and I lost focus. I've thought about purchasing FSDS, but wonder if there will be a big enough return, given that most aircraft I would ever want to fly in FSX are already there...just not the one I want, so it would be a purchase to do one aircraft and probably never any more.

So, take your shots or offer some advice...I've got both big shoulders and a willingness to learn something new.

Thanks for reading

Hey Randy, this is basically what I am Working on now. I have taken an abandoned C45 Twin Beech Tail Dragger, and have Stripped the Landing Gear, Installed Tricycle Gear, Rebuilt The Wing Tips, Installed Turbo Prop Engines, Rebuilt the Fuselage to Accommodate Wide Windows, and Reoriented the Door to Make it an Air Stair ! This will make it a Volpar Turbo Beech 18, Which is an Air America Modification. The Model I'm Working on, is the Original Gmax Model ! However You should be able to use Model Converter X, Import the *.mdl File, Export it as a *.3ds Object, then Import it into Gmax. You can look the Process up on the Web, ( *.3ds -> Gmax ), Its Pretty Simple. this is how I moved all My 3dsmax models into Gmax ! I have My Geometry Roughly Finished, and have started to Texture. Starting To Look Pretty Good ! Good Luck, Let Us know how You do !! - Johnman
Thanks for the encouragement, I appreciate it. Nothing quite so involved for me, but similar. My project will be to remove a set of Wasp Radials and replace them with PT6A Turboprops...that's it, everything else would be original. Gauges for controlling the TPs are already installed, just need to do the engine swap. I've used MCX to import a 3DS model in to GMAX before. I did it when I was replacing the prop blur on a FS9 model that also worked in FSX.



Resource contributor
Randy, it is absolutely possible. I created this:

From Deane Bauntons Cresco:

My greatest regret was that I was unable to create the chrome spinner that is on the actual plane:

To do so would have required I replace a perfectly working propeller animation and to me it wasn't worth the realism for what is to be an AI aircraft in a very large scenery. I contacted Deane and was quite thorough about it, both emails he had were defunct and I tracked him down, got a 90% certainty I'd found him on Facebook to no reply. I feel I have fulfilled my obligation and if I ever publish my freeware scenery, I will include the cargo drone.

Randy, forget about curves, that windshield cover tells you all you need to know. Start linking triangles to make a geodesic dome; but do it this way, this is how I taught myself to do boat hulls. Start with a large cube or block that covers your entire area. Think of it as a wood carving, and this is your start. Now, divide the block in 4 layers stacked. Of those four layers, divide those evenly, front to back, say 5 rows. On the top layer, draw the shape of the deck. Every line or curve you draw has to pass through intersections of the divisions you made. If these lines do not accurately follow the curves of the hull well enough, you would need to add more divisions. For this example, we'll keep it at 20 divisions. On the bottom layer, draw the keel. It can just be a straight line, if you want, or you can add some width so the bottom has a flat to it. When you are done, you should have four outlines progressing from top deck to keel. Do this again in the horizontal plane and you will have 5 more contours. A vertical line for the bow, maybe one for the stern and three hull shapes in between. Now, every intersection with the grid of every line you've drawn is to be the corner of a polygon. Connect all those intersections, remove the grid and mapping lines and you will have a very coarse boat hull.

The rest, you pretty much have. Model Converter X will isolate the parts you want to change and for me, FSDS was essential for creating required animations. Presumably Blender will do this, certainly Gmax will, but I use neither. Your biggest issue, I think, will be the size of the nacelles. This will require you to recreate the entire wing.

Thanks for the additional encouragement. At one point last night after reading johnman's post and then a little experimentation I was ready to toss it all in and just live with big radials on an aircraft with a swapped airfile and a modified aircraft config on a radial that "thinks" it is a turbine engine. It certainly worked, but the visuals were obviously wrong and just not appealing.

After seeing your work...stunning...and reading your post this morning I believe this morning it is time to give it another go and see what happens. Hopefully, because of the two wings involved being very, very similar in construction, shape, and size there will be little, if any, wing construct necessary. I've already reached out to the two authors/modelers/owners involved, but will avoid any screenshots or mention of the airframes involved until I have...if I have...permissions or "no reply" after a given time.

In the meantime...Blender was just confusing as could be and GMAX, while fine when I was doing non-animated, "square" buildings, for me was somewhat less daunting but still a trial with imported .3ds aircraft, even after isolating the parts in MCX before export. My first attempt at removing the big radials from the first model was just horrendous.

More to come...and again, Thanks for all the encouragement.



Resource contributor
Just a tip: if you don't know Blender, don't use it. A little Gmax experience can always be built on, but the two modelling tools are very different from a beginner's perspective. I'd say exactly the same about Gmax if you didn't know it but had a little experience of Blender.
Thanks for the tip Tom. I've been trying most of the and get this show started, but I always seemed to run in to a brick wall. I thought I'd start out with MCX and Sketchup since I am not dealing with animated parts (the props and prop spinner are separate from the engine powerplant and there are no animated parts within that housing.

Made very good progress at first. Got my PT6A's pared down to just the nacelle and engine housing. Removed the radials from the aircraft model by finding the part in the hierarchy listing in MCX and removing it. Only later did I realize that one single model part also contained the wheel well boxes, the windscreen trim, a few antenna, and some tail wheel parts. More on that later...but while I had gaping holes in the wings I merged the PT6As with the sans_engines model and I gotta admit, they looked pretty good. As Rick pointed out there will have to be some wing reconstruction. I started on that, but decided to hold off until I could find a way to remove just the engines without losing all the other parts. Tried isolating that model part in MCX, exporting it to Sketchup as a collada, removing just the engines, exporting back out as a collada, and then importing that result back in to MCX to merge with the aircraft model that was missing the extra parts, but had difficulty lining things up, so gave up.

Moved to GMAX, imported the entire aircraft model with the radials as a 3ds file, and thought I could get rid of just the engines in GMAX, but the same pieces...I should have realized that would be the case...made up that same single model part, so deleting one item deleted them all again.

Some things that frustrated me throughout the day. MCX loaded the textures associated with the model fine according to the event log, but they absolutely refused to display. I worked all day long with either checkerboard models or greyed out models. I didn't bother applying any texture to the cropped PT6A because I wouldn't have gotten it to display anyway.

Second, pretty frustrating when merging two models in MCX that I could not figure out a way to highlight the model that did not line up properly and using the Transformation/Move Tool to "nudge" it in to place. I would highlight the model part I wanted to move using the hierarchy table...and just that part...but when I tried to move just that part everything, including what I was trying to move it towards, moved so the gap always stayed the same distance. I spent the majority of my time loading the PT6A in to MCX, moving it more to where I thought it should go in relation to the merge, saving that model in the new position, merging, checking the positions...wash, rinse, repeat...sometimes twenty or thirty times.

Haven't given up, just taking a breather tomorrow...



Resource contributor
Randy, there is some apparent confusion. MCX is incredibly powerful at we often overlook that it is only a GUI from which to access the SDK tools. It really is a credit to Arno that we expect MCX to do 3d manipulation, just like Sketchup or 3ds Max and the fact is MCX simply can't. You must endeavor to make all your polygon arrangements outside of MCX. Essentially, when you use the transform tool, you do not move the model, you move the MCX focus on that model. When you have parts from combined models in MCX, MCX is only able to move it's focus in relation to the whole, it cannot distinguish movement of individual polygons.

The best way to do all this, imo, is to export the base of the model into your work space, Sketchup, Gmax, whatever. Use the isolate tool to get all parts of the model, but keep each part unique within your workspace. Now, when you need to add turboprops; access your exported wing assembly in the 3d software, remove exactly the wing, save the remainder, combine that result with your base model in MCX and now you have the same as started, including windshield trim and wheel boxes, minus the wing only. Go back to your 3d software and carefully edit the wind such that it lines up with the turbo nacelles and when it is adequate, use the merge tool to add it back to the model. At this point you should be able to add the turbo nacelles. If any of those parts included with the wing are animated, you will have to compile a new animation sequence for them, as it will have been lost by exporting to 3d software.
Thanks for the guidance Rick...need to do some flying today, but will tackle this later today and report back. Your help is very much appreciated.



Resource contributor
In Max/GMax, you can select the object that contains the engine(s), then go to the polygon sub-object level. Select only the polygons that encompass the engine(s) and delete them. The rest of the parts of that object (wheelwells, etc.) will remain intact.


Resource contributor
In Max/GMax, you can select the object that contains the engine(s), then go to the polygon sub-object level. Select only the polygons that encompass the engine(s) and delete them. The rest of the parts of that object (wheelwells, etc.) will remain intact.
Is this not only the case with an original .Max file and these sub groupings are lost, just like in the case with .skp native files, when the model is complied to another format? I I believe it is unlikely Randy will be able to access these groups from a model decompiled from .mdl format, can you confirm?


Resource contributor
Rick, it should still work. The compiler of the original .x and .xanim export files will auto-combine individual static parts that can share the same draw call. When decompiled from the .mdl format, those static parts that were combined to a single draw call will indeed show up now as a single object.

However, the individual polygons or vertices can be selected at the sub-object level (vertex or polygon) and deleted as desired. So yes, it does work. :cool:
Father Bill,

So nice of you to pop in here on a Sunday after church. I myself skipped church today feeling a little under the weather with a cold. Luckily, my pastor lives across the street from me and she understood. :)

Finished flying for the day and I don't think I have GMAX set up properly for modeling FSX models. I successfully isolated the engine/wheel well/tail wheel assembly in MCX and then exported as a .3ds (old) file. Imported that in to GMAX successfully. Edited out just the engines and saved the file, but when I went to export the result as an FS .mdl file I got all kinds of warnings. They were, in this order...

1. "Failed loading animation definition file from plugins\modeldef.xml" There are no animations on this part...the propellers are a separate part and not included and the tail wheel parts are static, no animation.

2. "No GUID set" ???

3. "No Friendly Name Set" ???

4. "Export Module Failure" ???

Obviously I have done something wrong...duh...but what I do not know. Looked for a good, easy to understand tutorial on modeling/modifying aircraft models in GMAX and Setting up GMAX to work with FSX, but wasn't real successful. I am sure they exist somewhere here in FSDevelopers but finding them is proving difficult.

Edit: At this stage I am really thinking I need to "bite the bullet" and purchase FSDS and start from scratch...only $50.00 at FSPilotshop and I've spent that much on dinner many times. I can go without eating for a day, right? Who knows, maybe I'll become a "Name" in the FS Modeling World like "n4gix" or "=rk="... :eek:

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Resource contributor
Before spending cash, spend time in the SDK, the section on New Aircraft Procedures especially. It's not that you're doing something wrong, so much as you're not doing some essential things. Plug and play this ain't.
Thanks Tom,

I have spent hours in the SDK and the GMAX program. I have the SDK for both FS2004 and FSX Deluxe. I have used GMAX that comes with the FS2004 SDK to create scenery objects, but never aircraft. The GMAX that comes with the FSX SDK looks fact I found two versions of it installed after some looking (so a total of three separate installs counting the FS2004 version). That's probably a part of my problem. My FSX install is on a separate hard drive (Z:\) no where near the FS2004 install on C:\.

FS2004 is in C:\Microsoft games. FSX is is Z:\FSX. The FS2004 SDK is in C:\Program Files (x86)\FS2004 SDK\. The FSX SDK is also in that same directory, but as \FSX SDK. Within that FSX SDK folder in the Environment Kit folder there is a folder called "FSX_GmaxGamePack". Inside that folder are four folders (Plugins, Scenes, Scripts, Textures) and two .ini files (gmax.ini and plugin.ini). Also in the Environment Kit folder is the Modeling SDK folder. Within that folder is another "FSX_GmaxGamePack" folder, with the same four folders plus a fifth, tutorials, the same two .ini files, plus the GMAX.exe executable.

Looking at the GMAX in the Z:\ drive where FSX is. Inside it is a lot...and I mean a LOT more files and folders. Best to just grab a screenshot and post rather than try to list them all...

So my problem is mostly ignorance on my part. I probably install the FSX GMAX at some point, later on couldn't find it, reinstalled it, and now even my system doesn't know where or what I'm doing. I confess, I haven't used GMAX since designing buildings to place in FS2004 with the FS2004 GMAX program.

Where oh where is the section called "New Aircraft Procedures"? Looked and searched and find nothing by that name?

Oh yes, since both had an executable I tried the engine switch with both the GMAX for FSX in C:\ and Z:\ The one in C:\ would let me at least select .3ds as the file type to export, and that is when I got the warnings I list above. The one in Z:\ only allows one type of file type to be exported, something called Plasma as a .P3D file type. Selecting the down arrow to populate a list of choices still only gives the .P3D file type.



Resource contributor
Ok, a situation with Gmax is that it has limited export capability, without the use of additional game packs. The thing about using Gmax, is that you have to learn how to install and activate the proper game pack, not rocket science, but as you've implied, has a few things to work out that are otherwise unrelated to development or modelling. Once installed and activated, you have to learn how to apply the special values, GUID, etc., which itself is another procedure. Now, I see that Gmax has .obj support as does MCX and if you can somehow get your model parts to Collada (.dae), MCX will automatically assign a GUID and model name, which you are required to manually apply in Gmax.

So, if you can get around the export issue, MCX will give you some quick and reliable results, that you can "sink your teeth into." It won't solve the animation pipeline, to complete that, you must be able to export from your animation software, Gmax or FSDS, to a format that will retain the animations and be readable by MCX. These formats are, .mdl, .bgl, .x/.xanim and .fsc (FSDS) and you will have to learn to manually assign model names and GUID's in that software, so, it seems like that is kind of a required step, as Tom has suggested.


Resource contributor
Okay, in both GMax and Max, you have to tell it where the export module is located.

1. Open GMax and click on Customize on the top toolbar
2. From the dropdown box click on Configure System Paths

4. From the box that opens, click on 3rd Party Plug-Ins
5. Click on Add
6. Browse to wherever you have the FSX SDK, installed and select the "FSX_gamepack"

7. When done, quite GMax and then launch it again. You should see FSX Tools and FSX Documentation on the top menu bar now, or as in my case with Max2017, Prepar3D Tools and Prepar3D Documentation.
Thanks to all who have responded. I am slowly making progress, but still unable to export...

As per previous posts you may remember I found multiple GMAX files in various locations and was unsure which one was doing what. Thus, I deleted all of them except the FS2004 version and then from the SDK reinstalled GMAX12. Set up my preferences and configured my path. FSTools is in the Top Menu Bar, but I don't see an FSX Documentation Tab.

I have successfully imported the engine/wheel well part from the aircraft I want to modify into GMAX as a .3ds file. There are no animations on this part. There is only the "Parent" identified as AA_LOD_400. Using the "Select" arrow I can click anywhere on the displayed model in GMAX and the entire model is highlighted. I then added two points at the leading edge of the radials (centered on the point where the prop spinner and propellers would be) for alignment so I would know where to place the PT6As. Then I chose the Modify/Element function and selected each radial and deleted them. Then I added the PT6A model to the scene and positioned it using the alignment point I added. The PT6A becomes identified as four "pieces", AA_LOD_100, AB_LOD_100, AC_LOD_100, and AD_LOD_100. Should their LOD match the AA_LOD_400 "Parent"? Each one seems to be a "Parent" also, though I would rather they were "Childs" of the AA_LOD_400 "Parent". Also, they be easier to manage if I combined them all into one part, but i cannot figure out how to do that.

I have been going through Milton Shupes series of Youtube Tutorials on GMAX. Up to Part 7 out of nearly 50 Parts right now, but I think they are geared toward FS2004 because I do not see the "FSTools" tab at the top of his menu bar so I am reluctant to continue watching them, although they were posted in 2017.

Still haven't been able to successfully export anything, although I have figured out the GUID SET and Friendly Name Set. I still get the Animation Warning, but I saw where Father Bill posted elsewhere that they were just warnings and would not prevent an export function from happening. However, I still get the export module failure. The GMAX setup instructions for FSX FSDevelopers Wiki says...
  1. Have a look in this SDK folder and then browse to the following folder: "Environment Kit\Modeling SDK". You'll see the folder FSX_GmaxGamePack.
  2. Copy the folder FSX_GmaxGamePack to the folder <gmax installation folder>\gamepacks
  3. Copy the GMax shortcut from <gmax installation folder>\gamepacks\FSX_GmaxGamePack to your desktop.
  4. Start GMax only from this new shortcut. Try it.
  5. Check if you see the "FS Tools" menu like the following screenshot:
I did that. GMAX typically installs a folder called "gmax" as in C:\gmax and all the files are installed there. It placed that "gmax" file on my Z:\ drive during install, not the C:\ drive because FSX is on the Z:\ drive, not the default install location. The FSX SDK, howver, is on the C:\ drive. Installing it way back when from my Deluxe FSX disks gave no other option that I recall. Is it possible during the export operation GMAX cannot find the SDK to compile everything?

Here's the screen I get...

Brainstorming here...making progress I think, but still a long way to go.

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Well, in trying to solve the "paths" issue I have really botched things up. Now, upon clicking the GMAX desktop icon to start GMAX I get these warnings before the GMAX panel even loads...

And after it loads I get this...

Took a look at gmax.log and found it to be empty.

Some reasons why I have this screwed up...beyond my own ignorance, which is great...

In trying to follow Father Bill's "configure path" post I don't see what he has pictured. His screen shows "Configure User Paths" and below it where his cursor is shows "Configure System Paths". My screen just says "Configure Paths". Where his screen shows "System" and "3rd Party Plugins" mine shows "General", "Plugins", "Bitmaps", and "xREF". Choosing "Plugins" I see...

Standard gmax plug-ins stdplugs
Additional gmax plug-ins plugins
FSX (the name I gave the entry) gamepacks\FSX_GMaxGamepacks\plugins

The third entry I added with the "ADD" button by browsing to the SDK, as Father Bill said, to C:\Program Files (x86)\FSX_SDK\SDK\Environmental Kit\Modeling SDK\FSX_GmaxGamePack. However, this is the same file "FSX_GMaxGamepack" that the FSDeveloper's Wiki said to copy and place in the gmax install\gamepacks\ location so I have two identical copies of the same folder, so not really sure which one I should be pointing GMAX to on startup. Logic says the one in the gmax install folder, but Father Bill said the one in the SDK folder. Perhaps a P3D vs FSX difference?

Okay...update...I finally got a project in GMAX to export as an FSX .mdl file, but it exported without any textures because I haven't made that far in the process yet. The modle was the windshield trim/wheel well/engines without the engines. It merged fine in MCX with the model I saved after removing the engines by deleting the engine parts from the I am closer.

When I import them they import without any textures, which probably isn't right, but a hurdle I'll cross later. I am just thrilled I got a model to export.

How? GMAX was still all screwed up, so once again I uninstalled it and reinstalled it, ignoring the FSDeveloper Wiki. So, I DO NOT have the FSTools Tab on the TOP Menu bar. I imported a .3ds model in to GMAX Vanilla with no "mods" to make it work for FSX. Then I tried to export that .3ds model making no changes to it. It worked fine, but the only file type option I had was .P3D (and I doubt that means Prepared 3 D...but maybe?

Anyway, because I was missing FSTools I looked in the FSX_GMaxGamePack folder of the SDK and opened each folder, copying whatever was in there to the appropriate folder in the gmax vanilla folder. Then I tried exporting again and was surprised that an FS Model file type was available for export. Tried it and got the animation\GUID\Name|export failed warnings. So I opened the MaxScripts Tab at the top menu bar and ran the LOD and Name worked!

Went back to the export as a .mdl file type and lo and behold it exported fine...without textures. Which brings up a question. In MCX when you load a model...any should load with liveries\textures...correct? Well, mine doesn't, even the default FSX aircraft like the Cessna 172 loads without textures, just a gray model. The correct livery or liveries are listed in the appropriate tab in MCX, but although I can select them, they do not show on the model? Curious.