NDO to STL Converter
FileFlip converts NDO to STL 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 NDO file to STL?#
- Drop your NDO 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 STL 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 STL file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting NDO to STL lose quality?#
Not in the sense of pixels or samples. Converting NDO to STL rebuilds the file in STL's own model rather than re-encoding it, so everything STL 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 NDO files online?#
Yes, because nothing is uploaded. FileFlip converts NDO 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 NDO to STL actually does to the file#
Converting NDO to STL 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 materials, textures and skeleton and animation.
| Engine | Assimp |
|---|---|
| Conversion path | One step: NDO → STL |
| 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 | Dropped | The target format has nowhere to put it. |
| Textures | Dropped | The target format has nowhere to put it. |
| Skeleton and animation | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- the target stores triangles and nothing else, so materials, colours, and texture coordinates have nowhere to go
- if the source carries a skeleton or animation, this target has no place to store it
What is an NDO file?#
An NDO file is Nendo's native mesh format, a binary file identified by a "nendo" header that stores an object's edge, face and vertex tables along with UV and texture data for Izware's subdivision modeller.
There's little reason to author new NDO files today; it matters only for opening a model saved by a copy of Nendo.
Convert NDO to OBJ or FBX to bring an old Nendo model into a modeller that's still maintained.
What is an STL file?#
An STL file is a triangle mesh created by 3D Systems in 1987 for its stereolithography 3D printers, storing nothing but a flat list of triangle facets and their normals, with no colour, material or unit of measurement attached.
Use STL when the only destination is a 3D printer's slicer, which is all the format was designed to feed.
Convert STL to 3MF when colour, material or unit information needs to travel with the geometry, since STL has nowhere to put any of it.
NDO to STL questions people ask#
What is an NDO file?
An NDO file is a Nendo model: an object's edges, faces, vertices and UV data stored in a binary file that starts with a "nendo" header. Nendo was a subdivision modeller from Izware known for a distinctive, box-free workflow built around edge and face selection.
Is Nendo still available to open NDO files?
No. Nendo's publisher, Izware, is no longer active, and there's no current source for the software, which means an NDO file today can only realistically be opened through a library like Assimp that includes a reverse-engineered NDO importer.
Is NDO related to Wings 3D?
Only by inspiration, not compatibility. Wings 3D, the open-source polygon modeller, describes itself as inspired by Nendo and Mirai, two earlier Izware applications, but Wings 3D does not read the NDO format itself.
What is an STL file used for?
An STL file is the standard input for 3D printer slicing software, storing a model's surface as a list of triangles with nothing else attached. Slicers use it to work out where to lay down material layer by layer.