BModel
From Blood Wiki
BModel (bsp model, submodel, mapobject model) is a model constructed in level editor out of brushes or patches and compiled into the .bsp file. Brush model can have triangle models attached (they become a part of the model). Doors, trains, platforms are bmodels.
BModel could be internal (supplied with the level and have special names such as *1, *2, *3 etc.) and external (BSP files). External BSP model differs from level file, it usually have no VIS data, entities, and other level-specific data.
Benefits
- very fast to render
- automatically get collisions
- supplied with level .bsp's (no external files)
- easy to construct in level editor (dont need a third party tools)
- can be lightmapped or lit dynamically (using lightgrid)
- can have triangle models attached
Drawbacks
- cannot be animated (only moved/rotated)
- badly optimized mesh (since it automatically generated from brushes)
- complex models with lots of corners or curved surfaces is not that easy to make