func_detail
A brush that renders normally but is excluded from BSP tree compilation and does not cast shadows. Used for decorative geometry that would otherwise create unnecessary BSP splits.
Notes
func_detail exists purely as a compiler hint. It renders and collides identically to a normal world brush, but the BSP compiler treats it as invisible when building the tree. This means it will not cause the compiler to split other brushes around it, which keeps the BSP tree clean and compile times fast.
Use it for:
- Decorative trim, pipes, railings, and small architectural details that don’t need to affect visibility or portals
Do not use it for structural geometry like floors, walls, or ceilings. Those brushes need to be part of the BSP tree so that the compiler can correctly seal the map and generate portals.
func_detail does not cast shadows. If a piece of geometry needs to cast shadows it should remain a world brush. This behavior may possibly be changed in the future.