SIB to USDA Converter
FileFlip converts SIB 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 SIB file to USDA?#
- Drop your SIB 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 SIB to USDA lose quality?#
Not in the sense of pixels or samples. Converting SIB 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 SIB files online?#
Yes, because nothing is uploaded. FileFlip converts SIB 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 SIB to USDA actually does to the file#
Converting SIB 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: SIB → 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 SIB file?#
A SIB file is Silo's native scene format from Nevercenter, holding the subdivision surface mesh and modelling data built up inside Silo's polygon modeller and UV mapper.
Keep a model as SIB while it's still being sculpted or UV-mapped inside Silo, to preserve the subdivision cage.
Convert SIB to OBJ or FBX once the model needs to move into another modeller or an engine, since almost nothing else reads SIB directly.
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.
SIB to USDA questions people ask#
What is a SIB file?
A SIB file is a Silo project, holding the subdivision surface mesh and modelling data from Nevercenter's Silo, a modeller focused on polygon and subdivision surface work with UV mapping. Silo also reads and writes a separate SIA project format alongside SIB.
Is Silo still available to open SIB files?
Yes. Unlike most applications with a format this obscure, Silo is still sold and actively updated by Nevercenter, with releases continuing well past 2020, so a current copy of Silo opens a SIB file without any special handling.
Can other 3D software open SIB files?
Not directly in most cases. Silo can export to more widely supported formats like OBJ, FBX and COLLADA, and that export is the usual way to move a Silo model into another application rather than that application reading SIB itself.
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.