### Filters

Filters - a way to identify physicals by their category.

- `detector` - invisible objects, serving as... detectors (whatever it means)
- `player`
- `monster`
- `bullet`
- `lair`
- `wall`
- `item`
- `door`
- `trap` - not used
- `region` - see: regions
- `obstacle` - barrels etc.
Additional:
- `hostiles` - monster, lair
- `friendly` - player
- `actors` - hostiles, friendly
- `static` - bullet, wall, item, door
- `moving` - detector, player, monster, bullet
- `nonmoving` - lair, wall, item, door
- `pathblocker` - wall, door
- `destructible` - actors, obstacle