model/x-3d MIME Type

Learn what model/x-3d identifies for classic Unreal mesh data, how its paired files work, and how Poly supports it.

MIME type details for model/x-3d

In active use
MIME typemodel/x-3d
Extensions
.3d
First standardizedUnknown
Created byUnregistered format convention
Browser support
Example applicationsUnreal Engine 1 tools, Unreal mesh viewers
Poly supportPartial. Poly supports recognized classic Unreal mesh sets when the required companion files are present.
Indexed by PolyYes. Poly indexes filenames and available scene metadata; companion scripts are not geometry records.
Preview in PolyPartial. Preview depends on a complete supported mesh set rather than an isolated `.3d` file.
Poly agentPartial. An optimized rendition of the 3D object or scene is provided to the agent when supported geometry is available.

What does model/x-3d represent?

model/x-3d is an unregistered, format-specific media identity used here for classic Unreal .3d mesh data. The reader expects a paired naming scheme: _d.3d for mesh data, _a.3d for animation data, and a matching .uc companion. It is not the MIME type for modern Unreal .uasset content.12

Browsers do not provide a universal viewer for this media type. The suffix and media type should be treated as clues, then checked against the file's structure and companions.

Opening and converting it

Keep the entire named set together and use a classic Unreal tool or a viewer that documents support for this format. Export to glTF or GLB for portable scene viewing, or FBX for Unreal-oriented workflows. Conversion may omit engine-specific animation and material conventions.

Support in Poly

Poly can preview supported geometry, index filenames and available metadata, and provide an optimized rendition of the object or scene to the agent. An isolated animation or data companion may remain searchable by name without a standalone visual result.

Footnotes

  1. Epic Games. Unreal Engine directory structure. Epic documents how engine and project assets are organized.
  2. Epic Games. Importing Assets Directly into Unreal Engine. Modern Unreal imports are saved as .uasset assets.
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