NFF to glTF Converter
FileFlip converts NFF to glTF 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 NFF file to glTF?#
- Drop your NFF 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 glTF 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 glTF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting NFF to glTF lose quality?#
Not in the sense of pixels or samples. Converting NFF to glTF rebuilds the file in glTF's own model rather than re-encoding it, so everything glTF 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 NFF files online?#
Yes, because nothing is uploaded. FileFlip converts NFF 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 NFF to glTF actually does to the file#
Converting NFF to glTF 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: NFF → glTF |
| 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, or a ZIP when the source carries separate materials or buffers |
| 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. |
Worth knowing before you start:
- the result is a single file when the model has no external materials or buffers, and a ZIP when it does
What is an NFF file?#
An NFF file is plain text written to Eric Haines' Neutral File Format, first drafted on October 3, 1988 as part of the Standard Procedural Databases project, listing a viewpoint, lights, a background colour and a handful of primitives like spheres, cones and polygons with one letter code starting each line.
Use NFF only when working with an existing ray-tracing benchmark scene or legacy renderer that already expects the format.
Convert NFF to OBJ when its primitives need to become a mesh that a modern 3D application can open.
What is a glTF file?#
A glTF file is a JSON scene description, developed by the Khronos Group and first released in 2015, that lists a model's meshes, PBR materials, animations and scene hierarchy while its binary geometry and textures sit alongside it in separate buffer and image files.
Use glTF's JSON form when a pipeline needs to inspect or hand-edit the scene structure directly, since it's plain, indexed JSON.
Convert glTF to GLB when the model needs to travel or load as a single file instead of a folder of JSON, buffers and textures.
NFF to glTF questions people ask#
What is an NFF file?
An NFF file is a plain-text scene description in Eric Haines' Neutral File Format, listing a camera, lights, a background colour and simple primitives like spheres, cones and polygons. Haines created it in 1988 as part of the Standard Procedural Databases project, a set of test scenes meant to let different ray tracers be compared on identical input.
What software can open NFF files?
NFF has no mainstream viewer today; support is limited to older ray tracers and a handful of 3D libraries, such as Assimp, that kept a reader for benchmark and archival purposes. A general-purpose 3D application is unlikely to open one directly.
Does NFF support textures or materials?
No, an NFF surface is described with only a fill colour, a diffuse and specular coefficient, shininess, transmittance and index of refraction, with no texture mapping at all. That simplicity is what made it easy for different renderers to implement consistently.
What's the difference between glTF and GLB?
glTF is a JSON text file that references its geometry buffers and textures as separate files, while GLB packs that same JSON, the buffers and the textures into a single binary file. Both describe the identical data model; GLB just bundles everything one file needs to travel as one upload.