JECS Server Authoritative Dust Field – 1,500 Entities on Custom Net (Blink)

This project is a JECS-only simulation of thousands of “dust” / firefly particles, driven entirely by:

• Pure ECS data (no server-side Instances)
• Custom networking using Blink
• Client-side rendering & effects

Compared to my other JECS RPG/Mob demo (which leans on Roblox physics and replication), this project pushes the opposite direction:

Turn Roblox into a pure data-sim and stream just the minimal deltas over a custom net layer.

With 1,500 dust entities, the system runs at around ~200 KB/s network intake (client), with smooth visuals and state changes.

Demo Place

https://www.roblox.com/games/129984384759966/Server-Simulation

Demo Video

Features

• 1,500+ dust entities simulated server-side
• Player interaction
  • Dust flees from predicted player movement direction
  • Push reactions when players run through dust
  • Neighbor “panic spread” to nearby dust
• Join-in-progress sync using bulk batched data
• Client-rendered visuals only

Architecture

• Pure JECS server world
  • No server Instances for dust; all data is ECS components
• Blink-based networking
  • SpawnDust – initial batch spawn
  • UpdateTransformDelta – movement deltas
  • UpdateTransformFull – periodic full syncs
  • UpdateDustState – flee state deltas
• Mailbox pattern for deferred, batched updates
  • Systems push PendingMovements and PendingStates
  • Networking drains and batches them every tick
• Tick rates
  • Simulation: 20 Hz
  • Networking: 12 Hz
  • Client Effects: 60 Hz
• Client ECS mirror
  • Client tracks Dust, Transform, DustData, DustState, Model
  • Drives color transitions and flee visuals

Benefits

• Scales to thousands of live simulated entities
• Demonstrates custom netcode design (delta + snapshots)
• Clean separation of server simulation vs client rendering
• Data-driven rarity, visuals, and behavior
• Production-ready architecture patterns (mailbox, batching, drift correction)

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