MDC to X3D Converter
FileFlip converts MDC to X3D 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 MDC file to X3D?#
- Drop your MDC 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 X3D 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 X3D file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting MDC to X3D lose quality?#
Not in the sense of pixels or samples. Converting MDC to X3D rebuilds the file in X3D's own model rather than re-encoding it, so everything X3D 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 MDC files online?#
Yes, because nothing is uploaded. FileFlip converts MDC 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 MDC to X3D actually does to the file#
Converting MDC to X3D 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: MDC → X3D |
| 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 MDC file?#
An MDC file is Return to Castle Wolfenstein's compressed variant of id Software's MD3 model format, storing most animation frames as small per-vertex byte deltas from a full base frame instead of complete positions for every frame.
Use MDC only when working directly inside Return to Castle Wolfenstein's modding pipeline, where the smaller animation footprint is the point.
Convert MDC to a modern interchange format when the model needs to leave that specific engine, since almost nothing outside its immediate tool ecosystem reads MDC.
What is an X3D file?#
An X3D file holds a 3D scene in the XML encoding of the ISO X3D standard, describing geometry, materials, animation and interactive behaviour for playback in a compliant browser or viewer.
Use X3D for scenes that need standards-track archival stability, or when a project already runs on X3D-based simulation or visualisation tools.
Convert X3D to glTF or GLB for anything shipping to a modern web page, game engine or AR viewer.
MDC to X3D questions people ask#
What is an MDC file?
An MDC file is a model in the compressed variant of MD3 built for Return to Castle Wolfenstein in 2001, storing most of its animation frames as small per-vertex deltas from a base frame rather than full positions for every frame.
How is MDC different from MD3?
MDC keeps MD3's structure, including the head, torso and legs split and tag-based attachment points, but compresses most frames down to per-vertex byte offsets from a base frame instead of storing complete vertex positions in every frame. That trades a small amount of precision for meaningfully smaller animation data.
What still opens MDC files?
The open-source iortcw engine, a modernized rebuild of Return to Castle Wolfenstein's engine, loads MDC files from the original game data. General-purpose viewers like Noesis also read MDC for inspection or conversion outside the game.
What replaced VRML?
X3D replaced VRML, carrying the same kind of web-delivered interactive 3D scene forward as an ISO standard first approved in 2004, with an XML-based encoding in place of VRML's plain-text syntax.