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Behaviors

Behaviors are modular steering passes that run each simulation step. Enable them in a SwarmBehaviorProfile assigned to your archetype. Most profiles only need two or three active behaviors.

Where to start

Game type Recommended behaviors
Default horde Approach And Surround, Personal Space, Idle Motion
Survivor-like crowds Approach And Surround (strong), Personal Space (moderate)
Melee packs Approach And Surround + Close-Range Pressure
Flankers / interceptors Add Predictive Catch-Up
Harassers / strafing enemies Orbit Style + light approach pressure
Loose crowd cohesion Small Hold Nearby Swarm (tune carefully against Personal Space)

Game view of swarm agents forming a ring around the player target, leaving the center open

Approach And Surround + Personal Space: agents spread into a ring around the target and hold the spacing instead of collapsing onto its center.

Simple mode field finder

The inspector's Simple mode surfaces a condensed set of fields organized into four blocks. Each field links to its full documentation in the Advanced subgroup pages.

Simple block Field Full documentation
Approach Target Approach Weight Approach & Surround
Approach Target Combat Standoff Surround Shape
Approach Target Surround Width Surround Shape
Crowd Spacing Spacing Strength Personal Space
Crowd Spacing Spacing Radius Personal Space
Close Range Combat Strike Distance Close-Range Pressure
Close Range Combat Attack Rhythm Close-Range Pressure — Simple-mode compound; drives Turn-Taking Cycle and Press Window together
Close Range Combat Max Active Attackers Close-Range Pressure
Close Range Combat Circling Weight Close-Range Pressure
Out-of-Sight Fallback Use Out-of-Sight Fallback Out-of-Sight Fallback

Runtime blending

Behavior steering is additive — the manager combines all enabled contributions, clamps the result to unit length, smooths it through the movement profile, and multiplies by Max Speed.

Key points:

  • Disable, don't zero. Several behaviors cost query budget even when their weight is 0. Disable the behavior fully when you want it gone.
  • Weights are relative. A weight of 2 on Approach with 1 on Personal Space means approach contributes twice as strongly before clamping.
  • Agent Spacing Radius Scale in SwarmSettings — 0 disables Personal Space entirely. Values above 1 expand effective spacing radii for approach, surround, and orbit.
  • Approach And Surround uses a built-in LOD. When Use Out-of-Sight Fallback is on, agents outside Sight Distance fall back to lost-target leader following; with the toggle off (the default), every agent always pursues directly. Adaptive slot solving only runs near the target for Full-tier agents.

Importance LOD and behavior cost

The LOD system (configured in SwarmSettings → Importance LOD) reduces behavior frequency for distant agents:

Tier Behavior cost
Full All behaviors run every step
Reduced Personal Space runs at reduced rate and with fewer samples. Adaptive surround and Close-Range Pressure skipped by default
Cheap Personal Space even less frequent, further-reduced sample cap

Tier thresholds are set by Reduced Quality Start Distance (Full → Reduced) and Cheap Quality Start Distance (Reduced → Cheap). Full Quality Agent Cap prevents cost spikes when many agents converge on one target.

Diagnosing behavior problems

When a behavior change has no visible effect, or an agent moves in an unexpected direction, use the Agent Debugger (Tools > Massive Swarm System > Agent Debugger). It shows the live steering contribution from each behavior for one selected agent, and lets you isolate or mute individual behaviors without editing profile assets.

See Agent Debugger for the full reference.

Behavior sections