You cannot send everything
In a large world with hundreds of entities, broadcasting the full state to every player every tick is impossible. Interest management decides, per player, which entities are relevant and sends only those.
Filtering by relevance
The core idea is an area of interest, often a radius or grid cells around the player. An entity is sent only if it falls inside that area.
- Entities outside view distance are culled entirely.
- Spatial structures like a grid or quadtree make the relevance query fast.
- As a player moves, entities enter and leave their interest set, triggering spawn and despawn messages.
Why it pays off
- Bandwidth scales with what a player can see, not with total world size.
- It also helps anti cheat, since players never receive data about enemies they cannot perceive.
- The server does more work, but that work is far cheaper than the saved network traffic.
Key idea
Interest management sends each player only the entities inside their area of interest, so bandwidth scales with perception not world size.