Blitz3D model MIME Type

What does model/x-b3d identify?

Poly uses model/x-b3d to identify Blitz3D model files with the .b3d extension. This is a Poly-recognized media-type label, not a claim of IANA registration. The format of the bytes still determines whether a file can be opened.

A .b3d file stores a Blitz3D model. Its binary chunks describe meshes, material brushes, texture references, bones, and animation keys. The format begins with a BB3D root chunk and can nest model nodes inside one another.¹

File structure and background

B3D grew out of the Blitz3D programming environment, where game-ready animated objects needed more than a bare triangle list. The published specification remains useful for understanding older assets.¹

A signature helps identify a candidate file, but does not validate its contents. Header values and the rest of the data must agree. Changing a filename or media-type label does not convert an unrelated file into this format.

Opening and working with the file

Use Blitz3D for an original Blitz project. Luanti also supports B3D models, particularly for animated game entities; it is a game engine rather than a general modelling editor.² For editing, keep the source project and use an exporter or importer that explicitly supports B3D. Installing Blender alone does not establish B3D import support.

A material can name a separate texture, so a model file is not necessarily the whole asset. Keep the original model and its companion images together. An untextured preview can still show useful geometry, but it is not evidence that the original character had no textures.

Support in Poly

Poly lets you orbit, pan, and zoom around supported geometry. Find the file by name, or use visual similarity once its visual content is available. The details panel shows available mesh, material, vertex, triangle, and other scene counts.

Game-specific material effects and external textures may differ from the original game. Available animation clips can be played when supported, but verify deformation in the target game before shipping an asset.

An optimized rendition of the 3D object or scene is provided to the agent, allowing compact yet information-rich multimodal interaction with 3D files. You can ask about the object's visible shape or compare assets, while retaining the original for authoring work.

Conversion choices

Choose glTF for modern scene exchange or OBJ for a static surface mesh. Before accepting a conversion, compare the silhouette and pose with the original game asset. A static export cannot preserve a character's motion.