BSP to USDA Converter
FileFlip converts BSP 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 BSP file to USDA?#
- Drop your BSP 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 BSP to USDA lose quality?#
Not in the sense of pixels or samples. Converting BSP 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 BSP files online?#
Yes, because nothing is uploaded. FileFlip converts BSP 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 BSP to USDA actually does to the file#
Converting BSP 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: BSP → 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 BSP file?#
A BSP file is a compiled Quake III Arena level: an entire map's world geometry, pre-partitioned into a binary space tree, along with its lightmaps, texture references and entity placements, not a model of a single object.
Use BSP to ship or run a compiled Quake III Arena level; the original engine or a source port loads it together with its PK3 to render the map.
Convert a BSP file mainly to inspect or reuse its geometry outside the original game, since the format isn't meant to be edited directly; going back to the level editor's source .map file is the normal way to make changes.
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.
BSP to USDA questions people ask#
What is a BSP file?
A BSP file is a compiled Quake III Arena level, holding the map's entire world geometry pre-sorted into a binary space partition tree along with its lightmaps and entity placements. It's a level, not a single model, so opening one gets you the whole map's geometry rather than a prop.
Can I get a single object or prop out of a BSP file?
Not directly. A BSP stores one specific map's geometry already merged and partitioned for that layout, so there's no clean way to pull out an individual piece without rebuilding the partition and visibility data from source. The original .map file the level was compiled from is the format actually meant for editing.
What opens BSP files today?
The open-source ioquake3 engine and games built on it, like OpenArena, load BSP files exactly as Quake III Arena did, and level editors such as GtkRadiant and NetRadiant compile and inspect them directly.
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.