COB to USDA Converter
FileFlip converts COB to USDA 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 a COB file to USDA?#
- Drop your COB 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 USDA 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 USDA file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting COB to USDA lose quality?#
Not in the sense of pixels or samples. Converting COB to USDA rebuilds the file in USDA's own model rather than re-encoding it, so everything USDA 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 COB files online?#
Yes, because nothing is uploaded. FileFlip converts COB 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 COB to USDA actually does to the file#
Converting COB to USDA 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: COB → USDA |
| 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 a COB file?#
A COB file holds a single object exported from Caligari trueSpace, its mesh, materials and scene-graph data stored as a sequence of tagged chunks such as PolH for geometry and Mat1 for materials, in either an ASCII or a binary encoding.
There's little reason to author new COB files; it matters for opening objects saved by a copy of trueSpace.
Convert COB to OBJ or FBX to bring a trueSpace-era object into a modeller that's still maintained.
What is a USDA file?#
A USDA file holds a USD scene written out as plain UTF-8 text, spelling out every prim, attribute and layer composition line by line, in the encoding Universal Scene Description calls its ASCII form.
Use USDA while authoring or debugging a layer by hand, or whenever a file needs to go through text-based diff and review.
Convert USDA to USDC once a layer is finished and only needs to load fast, not be read by a person.
COB to USDA questions people ask#
What is a COB file?
A COB file is a Caligari trueSpace object: a mesh with its materials and scene-graph data stored as tagged chunks. It's distinct from Truevision's COB video codec and from unrelated database or COBOL files that share the same extension.
Can I still open a COB file in trueSpace?
Only if you have a working copy. Caligari trueSpace was discontinued in 2009 after Microsoft's brief ownership of the company, and it hasn't been sold or supported since, so opening a COB file today usually means a converter or a library like Assimp rather than the original application.
What's the difference between COB and SCN files from trueSpace?
COB holds a single object; SCN is the same chunk format holding an assembled scene of multiple objects, lights and cameras. They're read by the same parser and differ only in what they contain.
What does a USDA file look like inside?
A USDA file is plain text starting with a line like #usda 1.0, followed by prims declared with curly-brace blocks holding their typed attributes, much like a structured configuration file. Any text editor shows it exactly as written.