Boids
by Tomate0613
Boids is a Fabric mob mod that makes fish move in flocks using the classic boids simulation, where each fish follows three steering rules.
What it does
Each fish in the mod steers itself using three rules based on the positions and headings of nearby fish: separation keeps individuals from crowding one another, alignment turns a fish toward the average heading of its neighbors, and cohesion pulls it toward the average position of the group. Together these rules produce schooling movement without any central controller.
Only the server needs the mod, so players join a server running Boids without installing anything. Fabric API is required and must be present on the server. Boids is released under the MIT License, and its source code is open source, with a public issue tracker. Files are available for 24 release versions, including snapshot builds, and the latest Fabric file is 2.0.0+26.3 for 26.3.
Key features
Separation between fish
Each fish steers away from neighbors that come too close, so the group does not collapse into one spot.
Heading alignment
Fish turn toward the average direction of nearby flockmates, which gives the school a shared course.
Cohesion toward the group
Each fish moves toward the center of mass of its local flockmates, keeping the school together.
Fish schooling behavior
The three rules combine into flocking motion for fish entities, with no commands or setup needed in play.
Gallery
Compatibility
Latest build for each game version and loader.
26.x5 of 5 versions with builds
1.21.x12 of 12 versions with builds
1.20.x7 of 7 versions with builds
This mod also publishes snapshot builds. Snapshots are not shown in the matrix.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Required by 2 mods
Use cases
Animated fish on a server
A server owner can add schooling fish to ocean or lake areas, where players see groups moving in coordinated patterns.
Learning the boids model
The mod shows how three local steering rules produce group motion, which suits anyone studying the boids algorithm.
Who it’s for: Server owners and players who want fish that swim in groups rather than alone. The mod is useful on Fabric servers, and players need nothing installed beyond the server itself.
Questions
Does Boids need Fabric API?
Do players have to install Boids?
Which game versions does Boids support?
In the catalog
Boids is one of 11,058 Mobs mods on ModsFinder, and one of 5,189 Mobs mods for Fabric. 8,071 mods support Minecraft 26.3.
More from Tomate0613
Similar mods
What the author says
In particular, each fish will follow these three rules: - Separation: steer to avoid crowding local flockmates - Alignment: steer towards the average heading of local flockmates - Cohesion: steer to move towards the average position (center of mass) of local flockmates
Official listing
- Modrinth page
- modrinth.com/mod/boids
- Owner
- Tomate0613
- Published
- 2023-12-27
- Updated on Modrinth
- 2026-09-16
- Facts verified
- 2026-10-15