AC3D Scene to DirectX X Converter
FileFlip converts AC3D Scene to DirectX X entirely inside your browser, using Assimp compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an AC3D Scene file to DirectX X?#
- Drop your AC3D Scene file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to DirectX X and the conversion starts on its own. FileFlip downloads 11.2 MB of WebAssembly the first time and nothing after that, then runs Assimp on your own machine.
- Save the DirectX X file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting AC3D Scene to DirectX X lose quality?#
Not in the sense of pixels or samples. Converting AC3D Scene to DirectX X rebuilds the file in DirectX X's own model rather than re-encoding it, so everything DirectX X can represent comes through exactly and anything it cannot has to be dropped. Expect the geometry to be exact, and anything the target has no place for, such as a rig, to be left behind.
Is it safe to convert AC3D Scene files online?#
Yes, because nothing is uploaded. FileFlip converts AC3D Scene files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What AC3D Scene to DirectX X actually does to the file#
Converting AC3D Scene to DirectX X runs on Assimp, downloads 11.2 MB of WebAssembly the first time and nothing after that, rebuilds the file in the target's own model.
| Engine | Assimp |
|---|---|
| Conversion path | One step: AC3D Scene → DirectX X |
| Downloaded to your browser | 11.2 MB, once, then cached by your browser |
| Quality | Rebuilt in the target's model |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Materials | Sometimes | Survives for some files and not others. |
| Textures | Sometimes | Survives for some files and not others. |
| Skeleton and animation | Sometimes | Survives for some files and not others. |
What is an AC3D Scene file?#
An AC3D file holds exactly the same plain-text scene data as an AC file, just saved under the modeller's full name instead of the short .ac extension, with the identical hierarchy of objects, surfaces and materials.
Use AC3D when a tool or pipeline specifically expects the long extension rather than .ac, otherwise the choice makes no difference.
Convert AC3D to OBJ or glTF for the same reasons you'd convert an .ac file: almost nothing outside the flight-sim world opens it directly.
What is an DirectX X file?#
An X file is Microsoft's DirectX mesh format, storing geometry, materials, textures, skinning and animation as a set of typed data templates, in either a human-readable text encoding or a tokenised binary one.
Use X only to keep compatibility with older DirectX SDK samples or a legacy pipeline built around the format.
Convert X to FBX or glTF for any current game or graphics pipeline, since DirectX itself has moved on from the format.
AC3D Scene to DirectX X questions people ask#
What's the difference between .ac3d and .ac files?
There is no difference in content. An AC3D file and an AC file store the same plain-text object hierarchy; .ac3d is just the modeller's full name used as an extension instead of the shorter .ac.
What software opens AC3D files?
AC3D files open in AC3D itself, and in FlightGear, which loads this format directly as its native aircraft and scenery model. Because it's the same format as .ac, anything that reads AC3D's short extension reads the long one too, though a few importers only check for .ac by default.
What is a DirectX X file used for?
An X file stores a 3D mesh for Microsoft's DirectX, including materials, textures, skinning and animation, laid out as a set of typed templates. It was the standard model format across the DirectX SDK samples through the 1990s and 2000s.
Is the X file format still used?
Rarely for new work. It's tied to Direct3D's Retained Mode API, which Microsoft stopped updating after DirectX 3.0 and later dropped outright, so current DirectX pipelines use FBX or glTF instead.