Open Game Engine Exchange .ogex
A readable, deliberately unambiguous game-asset format.
What an .ogex file holds
OpenGEX was designed by Eric Lengyel as a game-asset interchange format in which every construct means exactly one thing, an explicit reaction to the ambiguity of COLLADA and FBX. It is human-readable text built on the OpenDDL data-description language, and it carries geometry, materials, skinning and animation.
Commonly seen in: C4 Engine, game asset pipelines, Blender and Max exporters.
| Data | Stored in OpenGEX |
|---|---|
| Geometry | Yes |
| Materials and colour | Yes |
| Texture maps | Yes |
| Animation and rigs | Yes |
| Scene hierarchy | Yes |
| Read here | Yes |
| Written here | No |
Tested against a real file
The last sweep loaded Example.ogex from Assimp test models through the viewer on this site: 24 triangles across 2 meshes and 1 materials, in 2.1 seconds. Every format's result is on the test results page, run 2026-09-08.
Convert OpenGEX to another format
Every pairing has a page saying what survives the trip.
Other things to do with an .ogex file
Questions about OpenGEX
How do I open an .ogex file?
Drop it into the viewer on this site and it opens in the browser, with the scene tree, the materials and the mesh statistics. Nothing is uploaded. If you want it in another program instead, convert it to GLB, which almost everything reads.
Is OpenGEX a good format to archive in?
OpenGEX carries geometry, materials, textures and animation, so an archive copy keeps nearly everything. The usual caveat applies: a format is only as future-proof as the readers that exist for it, and .ogex is well served.
Does converting OpenGEX lose quality?
Geometry is copied vertex for vertex, so the shape does not degrade. What gets lost is whatever the target format has no field for: convert to STL and the materials go, convert to OBJ and the animation goes. The comparison table on each converter page says exactly which.
Formats that hold the same things
Or go back to the full format reference.