SMD to USDA Converter
FileFlip converts SMD 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 an SMD file to USDA?#
- Drop your SMD 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 SMD to USDA lose quality?#
Not in the sense of pixels or samples. Converting SMD 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 SMD files online?#
Yes, because nothing is uploaded. FileFlip converts SMD 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 SMD to USDA actually does to the file#
Converting SMD 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: SMD → 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 an SMD file?#
An SMD file is Valve's Studiomdl Data format, a plain text description of a mesh's skeleton, skin weights and animation frames that the GoldSrc and Source engines' studiomdl compiler turns into a game-ready model.
Write or export SMD when preparing a mesh or animation to compile into a GoldSrc or Source engine model with studiomdl.
Convert an SMD file when the mesh or animation needs to move into a modern DCC tool or engine outside the Source pipeline, since almost nothing outside Valve's tools reads it 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.
SMD to USDA questions people ask#
What is an SMD file?
An SMD file is Valve's plain text Studiomdl Data format, holding a mesh's skeleton, skin weights and animation frames as the source that Valve's studiomdl compiler turns into a compiled model for the GoldSrc or Source engine.
Does a Half-Life or Source engine game actually load SMD files?
No. SMD is only an intermediate, source-tool format; studiomdl compiles one or more SMD files, together with a QC script describing how they fit together, into a single .mdl file, and that compiled file is what the game loads.
What still creates or reads SMD files?
Blender, using the community-maintained Blender Source Tools add-on, is the standard way to export SMD files today, alongside older tools like MilkShape 3D that supported the format directly. The Crowbar tool also compiles SMD files into Source engine models outside Valve's own SDK.
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.