.bsp File Extension
File extension details for .bsp
Partial Support| File type | Quake III BSP map |
|---|---|
| MIME type | |
| Encoding | Binary little-endian map with an IBSP header, version 46, and lump directory |
| Operating systems | Windows, macOS, Linux |
| Opens with | GtkRadiant, ioquake3, Quake III Arena tools |
| Poly support | Partial. Poly supports the Quake III BSP variant with recognizable map geometry and related materials. |
| Indexed by Poly | Yes. Poly indexes filenames and available scene metadata; displayed counts are summaries, not individual searchable records. |
| Preview in Poly | Yes. Poly can preview supported map geometry, materials, and lightmap information. |
| Poly agent | Yes. An optimized rendition of the 3D scene is provided to the agent, allowing compact yet information-rich multimodal interaction with 3D files. |
What kind of file is a .bsp?
Here .bsp means the Quake III Arena binary space partition map format. A supported file begins with IBSP and version 46, followed by a directory of lumps for entities, textures, vertices, faces, lightmaps, and visibility data.1 The format is a compiled level, so it is normally opened with the game or a map editor rather than a general-purpose modeling tool.
The suffix is shared by other games. Poly's 3D support is for the Quake III variant documented here, not every BSP dialect used by Quake, Source, or other engines.
How do I open a .bsp file?
Use GtkRadiant or the matching Quake III based game. Keep referenced textures and the containing project or .pk3 archive available. GtkRadiant's documentation describes compiling source maps into BSP and packaging models and textures for the game.2 Exporting to glTF can preserve visible geometry, but game-specific entities, portals, shaders, and visibility behavior may be lost.
Poly support for .bsp
Poly can preview supported Quake III map geometry and associated materials. It indexes the filename and available scene metadata, and provides an optimized scene rendition to the agent. Entity text and every lump entry are not presented as separate searchable records.
Practical checks
Confirm the header and version before trying to open a file. If a map depends on textures in a .pk3, keep that archive beside it. Never assume that changing a different engine's BSP filename to .bsp makes it a Quake III map.
Footnotes
- id Software. Quake III Arena qfiles.h. The source defines the
IBSPidentifier, BSP version 46, lump constants, and lightmap dimensions. ↩ - id Software and GtkRadiant documentation. GtkRadiant Editor Manual. The manual describes BSP compilation and Quake III asset packaging. ↩