URBAN SPRAWL

Procedural City Simulator

Build sprawling metropolises with realistic traffic, dynamic economies, and stunning day/night cycles. Powered by Rust & Bevy for buttery-smooth performance with 100,000+ rendered entities.

>> Early Access Learn More
100K+ Entities @ 60 FPS
5,000+ Dynamic Lights
∞ Procedural Cities
Scroll to explore

Features

Everything you need to build the city of your dreams

[+]

Procedural Generation

Cities generated using tensor field algorithms create organic road networks and realistic urban layouts. Every city is unique.

[#]

Sandbox Mode

Full creative control with zone painting, road drawing, and building placement. Shape your city exactly how you envision it.

[>]

Traffic Simulation

Nagel-Schreckenberg cellular automata model with intersection logic, accidents, and congestion visualization.

[$]

Economic Systems

RCI demand, land values, employment, and population dynamics create a living, breathing economy.

[*]

Day/Night Cycle

Dynamic sun lighting with seasonal variations and weather effects. Watch golden hour wash over your skyline as windows light up one by one into the night.

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Landmark Buildings

Iconic structures including stadiums, train stations, clock towers, and distinctive skyscrapers.

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Weather System

Clear skies, fog, rain, and storms cycle dynamically. Wet surfaces glisten under street lamps.

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Industrial Zones

Heavy industrial with smokestacks and storage tanks vs. city industrial with loading docks and glass facades. Each density tells a different story.

[!]

GPU-Driven Rendering

Hardware instancing and clustered shading deliver stunning visuals with exceptional performance.

Built Different

Technical excellence under the hood

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Rust + Bevy

Built on the Bevy ECS game engine with Rust's performance and safety guarantees. No garbage collection pauses, ever.

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GPU Instancing

112-byte instance data enables rendering 100,000+ unique buildings with minimal draw calls.

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Clustered Shading

16x9x24 cluster grid manages 5,000+ dynamic point lights efficiently for vibrant nighttime scenes.

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Tensor Fields

Road networks generated using Chen et al.'s tensor field method for natural-looking street grids.

Architecture

Why Rust and Bevy instead of Unity or Unreal?

Traditional Engines

  • [GC] Garbage collection pauses
  • [OOP] Object inheritance hierarchies
  • [MT] Manual threading
  • [RT] Runtime overhead

Rust + Bevy ECS

  • [0] Zero-cost abstractions, no GC
  • [ECS] Data-oriented composition
  • [||] Automatic parallel systems
  • [N] Native speed, predictable perf

Entity Component System

All game logic lives in systems that query entities with specific components. This data-oriented design enables cache-friendly iteration over 100,000+ buildings without virtual dispatch or scattered heap allocations.

GPU-Driven Pipeline

Rendering offloads work to the GPU: compute shader culling rejects ~70% of geometry before draw, clustered shading manages thousands of lights, and indirect draw minimizes CPU-GPU sync. The simulation runs at a fixed 20 Hz tick rate, decoupled from rendering for deterministic updates.

Endgame Vision

Megastructures emerge as your city grows

The ultimate goal: massive procedural megastructures that emerge organically when demand and city scale reach critical thresholds. True endgame content for sprawling metropolises.

Residential & Commercial

Population-based thresholds

250K pop6×6 zones250m+
500K pop7×7 zones300m+
750K pop8×8 zones350m+
1M pop9×9 zones400m+

Industrial Megacomplexes

Job-based thresholds

50K jobs10×10 zones
100K jobs12×12 zones
150K+ jobs14×14 zones

Development Roadmap

Track our progress toward v1.0

v0.5

Core Foundation

Procedural generation, sandbox mode, basic simulation, save/load system.

[x] Complete
v0.6

Visual Polish

Seasonal variations, weather system, landmarks, traffic simulation, color grading.

[x] Complete
v0.7

UI/UX & Visual Identity

Zoom to cursor, land value heatmap, tool hotkeys, industrial zone differentiation, density-aware building visuals.

70% Complete
v0.8

Audio & Feedback

Ambient soundscape, UI sounds, notifications, simulation balance pass.

Planned
v1.0

Release Candidate

Full feature set, tutorials, documentation, final polish.

Future

Get Urban Sprawl

Early access coming soon - sign up to be notified

> EARLY ACCESS COMING SOON <
WIN

Windows

Windows 10/11 (64-bit)

[ Coming Soon ]
LNX

Linux

Ubuntu 20.04+ / SteamOS

[ Coming Soon ]
MAC

macOS

macOS 12+ (Apple Silicon)

[ Coming Soon ]

System Requirements

OS: Windows 10/11, Linux, macOS 12+
GPU: Vulkan 1.2 compatible (GTX 1060 / RX 580 or better)
RAM: 8 GB minimum, 16 GB recommended
Storage: 500 MB available space
changelog.txt - Urban Sprawl
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> CHANGELOG - All notable changes to Urban Sprawl
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[v0.7.0] - January 2026 (IN PROGRESS)
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>> Industrial Zone Differentiation

  [+] Heavy vs City Industrial - Distinct visual identity by density
      - Heavy (Low): smokestacks with smoke, storage tanks, pipes
      - City (Med/High): loading docks, modern equipment, glass facades
  [+] Density-Aware Facades - Heavy gets raw metal/concrete, City
      gets glass and painted modern finishes
  [+] Industrial Details Plugin - Smokestacks, tanks, docks, pipes
  [+] Shape Variety - City industrial gets Stepped, TowerOnBase,
      Composite shapes at higher densities

>> UI/UX Improvements

  [+] Zoom to Cursor - Mouse wheel zoom centers on cursor position
  [+] Land Value Heatmap - Toggle with L key
      - Red (low) -> Yellow (medium) -> Green (high) gradient
      - Grid-based sampling with inverse distance weighting
  [+] Tool Hotkey Indicators - Shortcuts shown on toolbar buttons
      - Zone tools (R/C/I), road types (1-4), actions (X/V)
  [+] Service Coverage Overlay - Better visibility
      - Bright edge ring around coverage circles
      - Doubled service radii for better gameplay
  [+] Building Info Panel - Height, floors, occupancy display

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[v0.6.0] - January 2026 [COMPLETE]
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>> Environment & Atmosphere

  [+] Seasonal Variations - Spring, Summer, Fall, Winter
      - Dynamic foliage colors and weather probabilities
      - Keyboard: 5-8 for direct season, N to cycle
  [+] Zone Color Identities - Distinct R/C/I palettes
      - Residential: warm tones (terracotta, cream)
      - Commercial: cool tones (corporate blue, steel)
      - Industrial: muted tones (aged brick, rust)
  [+] Color Grading System - 6 LUT presets (G to cycle)

>> Buildings & Architecture

  [+] Complete Landmark Set
      - Clock towers, churches, stadium, train stations
      - 4 iconic skyscraper styles (spire, pyramid, dome, crown)
  [+] Building Details
      - Interior mapping for windows (3D room illusion)
      - Balconies, storefronts, awnings, neon signs
      - Rooftop details (AC units, water towers, antennas)
  [+] NYC Firehouse & Art Deco Hospital models

>> Traffic & Vehicles

  [+] Complete Traffic Simulation
      - Nagel-Schreckenberg cellular automata model
      - Intersection priority, accidents, congestion (T key)
  [+] 7 Vehicle Shapes - Sedan, SUV, Truck, Van, Bus, etc.
      - Headlights, taillights, parking behavior

>> Simulation

  [+] Economic System - Zone demand, land values, employment
  [+] Population System - Daily schedules, needs, happiness
  [+] Building Lifecycle - Construction, aging, demolition

>> Rendering

  [+] PBR+ Materials - Roughness, metallic, parallax mapping
  [+] Post-Processing - Tilt-shift, grain, SSAO, bloom
  [+] Celestial Bodies - Moon and stars for night sky

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[v0.5.0] - December 2025 [COMPLETE]
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>> Core Features

  [+] Procedural city generation with tensor fields
  [+] Sandbox mode with zone painting
  [+] Day/night cycle with weather system
  [+] Save/load system
  [+] GPU-driven rendering with instancing
  [+] Clustered shading for 5,000+ lights
  [+] Rain and wet surface effects

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> EOF - Press [X] or ESC to close
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