Bmodel

A bmodel (short for brush model) is a model made out of BSP brushes. These are normally called from within the currently loaded BSP map file. Each bmodel uses its own BSP tree; there is a bmodel for worldspawn, as well as bmodels for each brush entity.

The struct used to define bmodels in bspfile.h is dmodel_t. The "D" might stand for "display", being consistent with other structs in the file.

With the exception of the bmodel used by worldspawn, bmodels are called from an entity using *# in the model KV, wherein # is an integer index representing the location of the bmodel in the BSP file. Worldspawn always uses bmodel 0, and does not require a model key; in fact, bmodel 0 cannot be loaded via the model key.

• In Quake, and by extension GoldSrc, any entity can use bmodels from a separate BSP file from the currently loaded map. If a bmodel is loaded from a separate BSP separate, the worldspawn bmodel will be used.

Note:All point entities can use MDLs, SPRs, bmodels, and separate BSP models interchangeably in Quake and GoldSrc.
Some brush entities, such as func_illusionary or func_healthcharger can be used as point entities this way, although the defined model must have been prechached.

Tip:In VHLT, pointing zhlt_usemodel to a cycler can be used to streamline this process, ensuring the entities are defined in the correct order in the compiled BSP.

Important:Bmodels contained in separate BSPs are usually fullbright, because they cannot inherit lighting info from the world.

Tip:Use ericw-tools and compile with -dirtdebug to apply some generic ambient occlusion to the standalone BSP model's lightmaps, improving visibility, or manually paint lightmaps with newbspguy.

• In Quake II, and by extension Source, only bmodels built into the current map can be used.^[confirm]

Note:Although the model KV is used for bmodels, sprites, and MDL models, they are not interchangeable in Source^[confirm]. In Quake II, only MD2 models and SP2 sprites are interchangeable.