AC3D Scene File Format (.ac3d)
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.
AC3D Scene at a glance#
| Full name | AC3D model |
|---|---|
| File extension | .ac3d |
| Category | 3D Models |
| Developer | Inivis |
| First released | 1994 |
| Other extensions | .ac.acc |
| Compression | Uncompressed |
| FileFlip support | FileFlip reads this format but does not write it |
What a .ac3d file can hold#
These are the things a AC3D Scene file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Textures and materials | Yes |
|---|
Strengths and limitations of AC3D Scene#
What AC3D Scene does well
- Byte-for-byte the same format as AC3D's .ac files, so every AC3D-aware tool reads it without conversion
- Plain ASCII text that stays readable and hand-editable outside AC3D
Where AC3D Scene falls short
- No skeletal rig or skinning, only a static per-object hierarchy
- The long extension is uncommon, so some importers that recognise .ac don't also check for .ac3d
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.
How to open a .ac3d file#
A .ac3d file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts AC3D Scene into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | AC3D, FlightGear |
| macOS | AC3D, FlightGear |
| Linux | AC3D, FlightGear |
| Web | FileFlip |
AC3D Scene 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.
Converting AC3D Scene files#
Convert AC3D Scene to another format
FileFlip does not write .ac3d files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.