Convert OFF to glTF

What carries over, and what does not

A format conversion is a translation, and translations lose things. Here is what actually happens when an OFF file becomes a glTF file.

This is a comparatively lossless pairing: 1 of the five categories above are supported by both formats, so most of what is in your OFF file has somewhere to go in the glTF file.

About Object File Format

OFF is about as simple as a mesh format gets: the word OFF, three counts, a list of vertices, and a list of faces indexing them. It comes out of Princeton’s Shape Benchmark and the geometry-processing world, which is where you still meet it: segmentation datasets, computational geometry papers and course assignments almost always ship OFF.

Commonly seen in: Princeton Shape Benchmark, MeshLab, CGAL, Geomview, academic datasets. More on the OFF format page.

About glTF 2.0 (JSON)

glTF 2.0 is the Khronos Group’s royalty-free runtime format, often described as "the JPEG of 3D". The .gltf flavour is human-readable JSON that describes the scene graph, and points at binary buffers and image files sitting next to it. It defines a single physically based material model, so a glTF file looks the same in every conforming renderer, which is rare in 3D. Use .gltf when you want to inspect or hand-edit the file, and .glb when you want to ship it.

Commonly seen in: three.js, Babylon.js, Godot, Blender, Adobe Substance 3D. More on the glTF format page.

How the conversion works

When you drop a file in, the bytes are handed to a parser compiled to run in your browser. The OFF data is decoded into an in-memory scene graph of meshes, materials and transforms, which is what the preview is drawing. Pressing convert walks that scene graph back out through a glTF writer and hands you the resulting bytes as a download.

The whole round trip is local. The page itself is static: it is delivered once and then does its work offline. That is why the privacy claim is checkable rather than a promise.

OFF to glTF: common questions