ACC to STEP Converter
FileFlip converts ACC to STEP 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 ACC file to STEP?#
- Drop your ACC 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 STEP 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 STEP file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting ACC to STEP lose quality?#
Not in the sense of pixels or samples. Converting ACC to STEP rebuilds the file in STEP's own model rather than re-encoding it, so everything STEP 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 ACC files online?#
Yes, because nothing is uploaded. FileFlip converts ACC 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 ACC to STEP actually does to the file#
Converting ACC to STEP 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, and drops skeleton and animation.
| Engine | Assimp |
|---|---|
| Conversion path | One step: ACC → STEP |
| 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 | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- if the source carries a skeleton or animation, this target has no place to store it
What is an ACC file?#
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.
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.
What is an STEP file?#
An STP file holds a STEP product model in ISO 10303's plain-text exchange syntax, encoding exact boundary-representation solids, surfaces and curves rather than a triangulated mesh.
Use STEP whenever exact CAD geometry, not an approximated mesh, needs to move between two different CAD systems.
Convert a STEP file to a mesh format like STL or OBJ once the model is finished and only needs to be viewed, rendered or 3D printed rather than edited as a solid.
ACC to STEP 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.
What does STP stand for?
STP is the file extension for STEP, the Standard for the Exchange of Product model data, formally ISO 10303. It's the neutral format mechanical CAD systems use to hand solid models to each other.