B3D to 3MF Converter
FileFlip converts B3D to 3MF 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 B3D file to 3MF?#
- Drop your B3D 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 3MF 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 3MF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting B3D to 3MF lose quality?#
Not in the sense of pixels or samples. Converting B3D to 3MF rebuilds the file in 3MF's own model rather than re-encoding it, so everything 3MF 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 B3D files online?#
Yes, because nothing is uploaded. FileFlip converts B3D 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 B3D to 3MF actually does to the file#
Converting B3D to 3MF 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, and drops skeleton and animation.
| Engine | Assimp |
|---|---|
| Conversion path | One step: B3D → 3MF |
| 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 | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- if the source carries a skeleton or animation, this target has no place to store it
What is a B3D file?#
A B3D file is the binary chunk-based model format of Blitz3D, storing meshes, textures, materials, a bone hierarchy and keyframe animation for games written in that BASIC-derived language.
Use B3D when working directly in Blitz3D or maintaining an existing Blitz3D game's asset pipeline.
Convert B3D to glTF or FBX to bring a rigged, animated model into a modern engine, since Blitz3D itself hasn't been actively developed in years.
What is a 3MF file?#
A 3MF file is a ZIP archive of XML documents, published by the 3MF Consortium in 2015 as 3D printing's replacement for STL, adding the colour, material, unit and multi-object placement data STL never had.
Use 3MF over STL whenever colour, material or multiple positioned objects need to travel with the geometry to the printer.
Convert 3MF to STL only when the destination software is old enough to not support 3MF at all.
B3D to 3MF questions people ask#
What is a B3D file?
A B3D file is a 3D model in Blitz3D's native binary format, storing a mesh along with its textures, materials, bone hierarchy and keyframe animation. Blitz3D was a BASIC-derived language and engine popular for small, hobbyist games in the early 2000s.
Does a B3D file support animated characters?
Yes. A B3D file can store a full bone hierarchy with vertex weights and keyframed position, scale and rotation data, which is more than many game formats from the same era managed.
What software opens B3D files?
Blitz3D itself is the primary application, since the format was built specifically for it. Blitz3D and BlitzPlus were released as open-source software in 2014, which is why later third-party tools have been able to add B3D support.
What is a 3MF file?
A 3MF file is a 3D printing format, a ZIP archive of XML, published by the 3MF Consortium in 2015 to replace STL. It adds colour, material, real-world units and multiple objects with their placement on the build plate, none of which STL can store.