Galaxy Generation

This page is a Work in Progress as much of the lore/Development for the game is yet to be established.

The Galaxy Generation system in Starship Simulator is responsible for creating the vast, explorable 1:1 scale representation of the Milky Way galaxy featured in the game. It uses a combination of procedural generation techniques driven by astrophysical principles and integrated real-world astronomical data.

Core Principles & Scale Management

The system employs several key strategies to manage the immense scale of the galaxy and provide a seamless experience:

• Sector-Based Structure: the galaxy is divided into millions of cubic sectors, each 100 light-years on a side (100ly³).
• Sub-Sectors: each 100ly³ sector is further subdivided into 1 million cubic sub-sectors, each 1 light-year on a side (1ly³), which serve as locations for content like star systems. Star systems occupy a single sub-sector and cannot exceed 0.5ly in radius.
• Unique Seeds: each 100ly³ sector is generated using its own unique seed, allowing for isolated generation and preventing changes in one sector from affecting others. Different classes of sub-sectors also utilize distinct seed pools. An upgraded seed system providing 2²⁵⁶ unique seeds was implemented in Build 0.225.0.21.
• Coordinate System: a 64-bit Cartesian coordinate system is used. The system was re-based during development to place the true galactic centre, Sagittarius A*, at coordinates 0,0,0 (Build 0.225.0.14, 0.225.0.16). Sol is located at coordinates -26670, 0, 56.
• Origin Re-basing: in order to maintain precision, the player's local coordinate origin is continuously re-based relative to the sub-sector they are in, ensuring the player's ship effectively never travels more than 0.5 light-years from its current local origin point.
• Seamless Travel: this system enables travel across the galaxy, including warp drive jumps, without loading screens.

Data Sources

The galaxy simulation incorporates various data sources:

• Procedural Generation: algorithms based on astrophysics generate the majority of stars, planets, and phenomena, filling gaps where real-world data is unavailable.
• Real Star Data: information from real-world astronomical surveys (like the Gaia catalogue mentioned in development) is integrated, including millions of stars within a significant radius (e.g., 2000ly mentioned in Build 0.225.0.21) of Sol. Specific nearby stars (like Sirius, Alpha Centauri, Barnard's Star, Wolf 359) and Sol system objects are included (Build 0.225.0.16, 0.225.0.67). Data is retrieved by means of SQL database integration during the generation process.
• Backer Contributions: systems and races designed by backers are integrated into the galaxy using database lookups (Build 0.225.0.39, 0.225.0.79).
• Modding Support: a local SQLite file (`stars_modded.db`) allows players to add custom star systems locally (Build 0.225.0.79).
• Custom Content: the system allows for specific procedural sectors to be replaced with hand-crafted ones for bespoke content or missions.

Galaxy Structure & Stellar Distribution

The simulation models the known large-scale structure of the Milky Way (see The Galaxy In Detail):

• Components: includes representations of the Galactic Core, Bulge, Disc, Stellar Halo, Globular Clusters, Open Clusters, and potentially stellar streams and emission nebulae.
• Density Map: a large format greyscale density map defines the overall shape and stellar density distribution, where each pixel represents a 100ly³ sector.
• Stellar Density: densities within sectors range from 0 up to 8,000 stars, based on the density map value.
• Vertical Distribution: the distribution of stars above and below the galactic plane within a sector is calculated mathematically.

Generation Process

The galaxy and its systems are generated dynamically as the player explores:

• Galaxy Generation (Triggered by Movement): when the ship moves significantly (trigger points exist at 100ly and 1ly intervals), the system calculates data for a 3x3x3 grid of sectors around the player. For each sector, it reads the density map, assigns seeds, generates FTL civilizations, retrieves stellar data from databases, determines the sector's political state and galactic region type, generates sub-sector locations (prioritizing larger features first), and creates a textual description. Data from these sectors is combined, filtered by distance (within 50ly for performance - Build 0.225.0.54), sorted by distance to the ship, and broadcast (typically several thousand locations) for use by systems like Sensors. Generation speed optimisations were a focus in development (Build 0.225.0.16, 0.225.0.21).
• Star System Generation (Triggered by Arrival/Scan): when a player enters a system or scans it deeply, the detailed system generation process begins. This involves:
  • computing stellar data (sub-class, mass fractions, escape velocity, Roche Limit, Habitable Zone, etc. - refined in builds like 0.225.0.30, 0.225.0.67)
  • creating a proto-planetary disk (considering H/He/Metals, lifespan, Hill radius - implemented Build 0.225.0.32)
  • calculating stellar temperature regions (determining Habitable Zone, Frost Line (~150K), Dust Sublimation Line (~2000K) - Build 0.225.0.66, Lava Line (~1200K))
  • iteratively determining planet orbits (using a formulation related to the Titius-Bode Law)
  • for each potential planet: core mass accretion -> determining Rocky vs. Gas Giant (based on escape velocity vs. H2 thermal velocity - Build 0.225.0.32) -> calculating physical characteristics -> determining atmospheric composition -> assigning final planet type -> generating life flag -> deducing mass from the proto-disk
  • generating a Kuiper Belt equivalent once the main disk mass is depleted (Build 0.225.0.67)

Planet Characteristics

Generated planets have detailed, calculated properties including:

• Orbital Mechanics: orbital distance, period, velocity (Build 0.225.0.69)
• Physical Properties: mass, radius, volume, gravity, core/mantle/crust densities, Roche Limit, Hill Radius (Build 0.225.0.30, 0.225.0.69)
• Atmosphere: presence/absence determined by factors like gravity and temperature; composition calculated (e.g., chemicals for gas giants, "tenuous exospheres" for airless bodies - Build 0.225.0.31, 0.225.0.70)
• Temperature: equilibrium and surface temperatures calculated based on stellar output, Bond Albedo, greenhouse effects, etc. (Build 0.225.0.69)
• Surface Features: basic surface maps generated for Sensors/Holoprojector (Build 0.225.0.48, 0.225.0.70), incorporating Nanite tessellation for visual detail (Build 0.225.0.70, 0.225.0.72)

Life and Civilization

The system generates alien life and civilizations:

• Life Generation: a "Has Life?" flag is determined during planet generation (Build 0.225.0.30), influenced by factors such as the Habitable Zone. Confirmation requires detailed Short Range scans (Life and Tech Signatures, Build 0.225.0.69).
• Civilizations: alien civilizations are generated throughout the galaxy
  • Their chance of appearing is tied to the sector type
  • Their technology level (ranging 0-100) is determined by the age of their star system (Build 0.225.0.63)
  • FTL-capable civilizations are generated "in isolation". Non-FTL civilizations occur naturally based on planetary conditions during system generation
  • Random alien race names are generated (with blacklist filter - Build 0.225.0.69)
  • Detection relies on Tech Signatures (Level 1 Knowledge / Long Range Scan - Build 0.225.0.63) and Life Signatures (Level 3 Knowledge / Short Range Scan)

Implementation & Consistency

• Isolated Generation: generating sectors independently prevents cascading changes if generation logic is updated
• Hand-Crafted Content: the system allows developers to replace any procedurally generated sector with bespoke, hand-crafted content
• Code Stability: the developers aim to lock down the core galaxy-generation code as much as possible once finalized to ensure consistency
• Multiplayer Handling: galaxy generation runs locally on client machines for improved performance in multiplayer (Build 0.225.0.60)
• In-Game Hardware Representation: a physical box representing the Galaxy Generation computer exists in the Data Centre on C Deck (Build 0.225.0.60)

Interaction

Players primarily interact with the generated galaxy via the Sensors suite, which reveals progressively more detail about systems and celestial bodies based on scan type, proximity to a target and achieved knowledge levels. The Holoprojector provides visual representations on orrery models. Navigation data is used by the Helm.

On the dev stream Starship Simulator - Random F̶r̶i̶d̶a̶y̶ Saturday! (Planetary Landings) on 2025-12-06 Dan started the background work for Planetary Landings with a planned feature in which players gain the ablility to take a shuttle from the ship and take it to a planet's surface to explore. A basic proof of concept feature was created and released on Development Build 0.226.0.16 where players can use a hidden teleport in a bridge-adjacent room to access the planet. This will not be available for the public patch until it is implemented fully and falls within the patch cycle of the Roadmap. Further development was made on 2025-12-12 where an improved planet genaration surface map code was created within the engine to give better surface reproduction.

Future Expansion

Planned additions and refinements to the galaxy simulation include:

• wormholes
• rogue Planets (added for Demo 4 update)
• moons and multi-star systems
• visible Proto-planetary disks
• volumetric Planetary Rings
• volumetric Gas Giants
• planetary Nebulae (added for Demo 4 update)
• real World Nebulae & Sci-fi Nebulae
• comets
• Oort Clouds
• more Stellar Classes

Sources

• Fleetyard Studios Pitcon Presentation #2 (April 2025) - slides available Here. - Fleetyard Studios Pitcon Presentation #2 Video Recording (Segment: 2:46:30 - 3:24:00) - Link
• Development Build Update History (Various entries referenced above)
• Dev Streams