Massive Swarm System

Built for Unity 2022.3 LTS, ready for Unity 6.

Massive Swarm System drops a thousand-plus enemies into a plain Unity GameObject project and holds your frame rate while they swarm. It's the missing piece for games where the threat is the crowd itself.

One Swarm Manager ticks the whole swarm in a single loop: no per-agent Update, no DOTS or ECS rewrite, no NavMeshAgent baking. Everything is in the box: simulation, navigation, spawning, behaviors, and the VAT animation baking tools, with nothing else to buy. The core runtime references nothing beyond the engine, so it compiles in a bare project. Agents chase, surround, hold their spacing, and pile on pressure as a crowd, all driven by data instead of a script on every enemy. You stay in the GameObject workflow you already know.

It's made for survivor-likes, bullet-heaven games, zombie hordes, and arena survival: any 3D game where the pressure comes from sheer numbers and how they move, not from per-unit orders or scripted set pieces.

At a glance
- 1000+ agents at frame rate from a single centralized simulation tick
- Everything included: no paid add-ons, no GPU instancing or animation packages to buy
- Plain GameObject workflow: no DOTS, ECS, or extra packages for the core runtime
- Approach & Press, Personal Space, Orbit Style, and Retreat behaviors out of the box
- Importance LOD keeps a pile-on around the player inside the frame budget
- Simulation and visuals decoupled: render with pooled MeshRenderers (SRP Batcher) or GPU-instanced VAT.
- One-click setup and a scene-view overlay get your first swarm running in minutes
- Surface Flow Field navigation for levels with walls, stairs, and uneven floors

Performance & scale
- Measured on named hardware in a release build: 3,848 agents at 63 FPS (15.8 ms) in the Pyramid demo scene, with every one of them on screen. Intel i7-10700K, NVIDIA RTX 3080, Unity 2022.3.62f2, 1440p on the High Fidelity tier with dynamic shadows and camera effects on. Download the same demo and read the same counter yourself.
- It holds up on a phone too. A release APK runs 1,124 agents at 40 FPS on an OPPO A74 5G, Performant tier, 1440p at 60% render scale, with shadows and camera effects on and the player alive in a dense crowd.
- Manager-driven simulation: the whole swarm updates in one tick, with no per-agent Update, FixedUpdate, or LateUpdate
- Dense internal agent data built for scalable movement and behavior
- Spatial grid for spacing, neighbor checks, and body blocking
- Importance LOD tiers that scale behavior and visual cost by how much each agent matters
- Inspector performance hints and a live stats overlay to measure and tune on-device

Behaviors & navigation
- Seven behavior passes you mix per archetype: Approach & Press, Personal Space, Retreat, Group Pull, Predictive Catch-Up, Orbit Style, and Idle Motion
- ScriptableObject movement and behavior profiles you tune in the inspector
- Automatic target registration with multi-target support and retargeting hysteresis
- Surface Flow Field navigation for walls, stairs, and uneven floors

Spawning & setup
- Rect and ring shape spawners
- A Spawner Director to coordinate multiple spawners for ambushes and maintained hordes
- Agent archetypes bundling prefab, radius, push resistance, and the movement, behavior and attack profiles
- Welcome window, scene-view create buttons, and an archetype wizard with five ready presets: Zombie Horde, Sword Mob, Skittering Bug, Ranged Skirmisher, and Custom (Defaults)

Visuals & rendering
- Pooled visual GameObjects that follow the simulation data
- Visual interpolation for smooth movement at any tick rate
- Optional Animator-based visual syncing
- Optional VAT animation workflow for high-count animated enemies, with VAT Baker tools included and an SRP Batcher compatible shader

Damage, source & integration
- Attack profiles with optional swing and contact damage, each with its own reach, timing and pushback strength
- Damage interfaces that hand your own health system the hit point, direction, normal and pushback strength, so the reactions stay yours
- Knockback runs both ways. One call sends agents flying, and you set how long before their own steering takes back over
- Full C# source, no DLLs
- Core runtime is render-pipeline-agnostic and references nothing beyond the engine, with the optional Input System helpers in a separate assembly. The included visuals need URP, because the VAT shader is URP-only
- The samples ask for more, all of it free: StarterKit wants TextMeshPro, and FullDemo wants TextMeshPro, Cinemachine 3.x and the Input System. Delete a sample folder and its requirement goes with it
- Debug tools and gizmos, sample scenes and prefabs, and offline documentation