ACC File Format (.acc)
An ACC file is AC3D's plain-text .ac format with one addition, a triangle-strip surface type that TORCS and Speed Dreams use for car and track models with smoothing and baked shadow mapping that plain AC3D scenery doesn't carry.
ACC at a glance#
| Full name | AC3D model |
|---|---|
| File extension | .acc |
| Category | 3D Models |
| Other extensions | .ac.ac3d |
| Compression | Uncompressed |
| FileFlip support | FileFlip reads this format but does not write it |
What a .acc file can hold#
These are the things a ACC 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 ACC#
What ACC does well
- Reads with the exact same object hierarchy and material system as AC3D's own .ac format
- The triangle-strip surface type lets TORCS and Speed Dreams bake smoothing and shadowing straight into a track model
- Text-based, so a track built by the trackgen command-line tool can be inspected or hand-tweaked afterward
Where ACC falls short
- Effectively a single racing-sim community's extension, so support outside TORCS, Speed Dreams and AC3D itself is thin
- No skeletal rig or animation, the same limitation the base AC3D format has
- No formal specification separate from AC3D's own, so the triangle-strip extension is documented mainly in the tools that use it
Use ACC when building or editing a car or track for TORCS or Speed Dreams, since their tools expect the extra surface type.
Convert ACC to OBJ or glTF for anything outside the TORCS and Speed Dreams pipelines, where the format is rarely supported.
How to open a .acc file#
A .acc file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts ACC 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, Blender (with an ACC import/export script), Speed Dreams |
| macOS | AC3D, Blender (with an ACC import/export script) |
| Linux | AC3D, Blender (with an ACC import/export script), Speed Dreams, TORCS |
| Web | FileFlip |
ACC questions people ask#
What is an ACC file?
An ACC file is a 3D car or track model in the format TORCS and Speed Dreams use, which is AC3D's plain-text .ac format plus one added surface type for triangle strips. Track designers commonly build it with Blender using a community ACC import/export script, or generate it with the trackgen tool.
Is ACC the same format as AC3D's AC file?
Almost. ACC shares the same object hierarchy, materials and text structure as an AC3D .ac file, so the same parser handles both. The only difference is a triangle-strip surface type TORCS and Speed Dreams added for smoother, shadow-mapped car and track geometry.
Can AC3D open ACC files?
Yes, AC3D opens ACC files the same way it opens .ac files, since the underlying format is identical apart from the added surface type. Racing-sim tools like TORCS and Speed Dreams are what actually make use of that extra data.
Converting ACC files#
Convert ACC to another format
FileFlip does not write .acc 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.