Routing¶

Routing is how items choose their path when multiple directions are available. Different pipe types use different routing strategies.

When Routing Happens¶

Routing decisions occur when an item reaches the center of a pipe and multiple exit directions are available.

If only one direction is available, the item takes that path automatically (no routing decision needed).

Routing Strategies¶

Random Routing (Tier 1)¶

Used by: Stone Transport Pipe, Copper Transport Pipe

Randomly selects from available exit directions
No item awareness
Simple and unpredictable
Suitable for early networks with single destinations

Directional Routing (Tier 1)¶

Used by: Item Merger Pipe

All inputs route to single configured output
Output direction set with Wrench
Items cannot enter through output face

Filter-Based Routing (Tier 2)¶

Used by: Item Filter Pipe

Routes based on per-side item filters
Configure which items go to which faces
Unmatched items route to unfiltered directions
Items drop if no valid route found

Inventory-Preference Routing (Tier 2)¶

Used by: Item Insertion Pipe

Prefers directions with accepting inventories
Falls back to pipe directions if no inventory
Items drop if no valid output

Deletion (Tier 1)¶

Used by: Item Void Pipe

"Routes" items to deletion
Items disappear at pipe center
No actual exit direction chosen

Routing Priority¶

When multiple pipes could make routing decisions, the pipe's module evaluates in order: 1. First module to return a decision wins 2. If all modules pass, default random routing applies 3. Empty direction list results in item drop

Invalid Routes¶

Items drop as entities when: - No valid exit directions available - Filter pipe has no matching filter and no unfiltered exits - Insertion pipe finds no accepting inventory or pipe - Routing module returns empty direction list

Building Reliable Routes¶

For Tier 1 networks: - Use Item Merger Pipes to guarantee direction - Design single-path routes where possible - Accept randomness for multi-destination networks

For Tier 2 networks: - Use Item Filter Pipes for deterministic sorting - Use Item Insertion Pipes to prefer storage - Combine both for complex routing logic

General tips: - Minimize junctions when path matters - Use Item Void Pipes for overflow - Test networks with small item batches first