Stellar Sky Mod Wiki

Stellar Sky is a visual and mechanical overhaul mod that transforms the simplistic Minecraft sky into a realistic celestial sphere. It replaces the static sun and moon textures with dynamic celestial bodies based on real-world astronomical data. The mod simulates the movement of stars, planets, and the Milky Way, allowing players to experience a sky that changes based on their in-game location, time of day, and the current season.

The mod is highly configurable, allowing players to adjust the length of days and years, the brightness of celestial objects, and even the latitude and longitude of their world to change how the stars rotate around the poles.

Stellar Sky introduces several types of celestial bodies, each with unique rendering properties and movement patterns.

Stars and Constellations

The mod utilizes the Yale Bright Star Catalog to render approximately 9,000 real-life stars. Each star is rendered with its actual color (based on B-V index) and magnitude (brightness). As the world rotates, these stars move across the sky, forming recognizable constellations such as Orion, Ursa Major, and the Southern Cross.

Planets

Stellar Sky simulates the movement of the major planets in our solar system. Unlike stars, which remain fixed relative to each other, planets move along the ecliptic plane over time. The following planets are visible:

• Mercury: Often close to the sun, visible during twilight.
• Venus: The brightest planet, often appearing as the 'Morning Star' or 'Evening Star'.
• Mars: Distinguishable by its reddish hue.
• Jupiter: A bright, steady light in the night sky.
• Saturn: Visible to the naked eye as a yellowish star-like object.

The Sun and Moon

The default Minecraft sun and moon are replaced with realistic versions. The sun's size and color change slightly based on its position in the sky (atmospheric scattering), while the moon features accurate phases and a realistic orbital period. The moon's size can be adjusted in the configuration to appear more cinematic or more realistic.

The Milky Way

A high-resolution texture of the Milky Way galaxy is rendered in the background, providing a faint, misty band of light that stretches across the celestial sphere. Its intensity can be adjusted to suit the player's preference for light pollution.

The mod introduces several deep mechanics that govern how the sky behaves and how it interacts with the Minecraft world.

Celestial Rotation

The sky rotates around a celestial pole, the position of which is determined by the world's Latitude.

• At the Equator (0°), stars rise vertically and set vertically.
• At the Poles (90° or -90°), stars move in horizontal circles around the zenith.
• Intermediate latitudes result in the slanted paths typical of most real-world locations.

Time and Seasonal Cycles

Stellar Sky allows for the decoupling of the day/night cycle from the standard 20-minute Minecraft day.

As the year progresses, the sun's path shifts higher or lower in the sky, and the stars visible at night change, simulating the Earth's orbit around the sun.

Atmospheric Effects

The mod calculates atmospheric refraction and scattering. This means that objects near the horizon may appear slightly displaced, and the sky color transitions smoothly through various shades of blue, orange, and purple during sunrise and sunset.

Stellar Sky includes a customizable Head-Up Display (HUD) that provides astronomical data to the player. This is essential for players who wish to navigate using the stars or track the passage of time accurately.

HUD Elements:

• Solar Time: Displays the time based on the sun's position (e.g., 12:00 PM is solar noon).
• Tick Time: The current time in Minecraft ticks.
• Date: The current day and year in the simulation.
• Horizontal Coordinates: Displays the Azimuth (compass direction) and Elevation (height above horizon) of the object the player is looking at.
• Equatorial Coordinates: Displays Right Ascension and Declination, used for locating specific stars.

The mod is famous for its extensive configuration options, which are split into Client-side (visuals) and Server-side (mechanics).

Client Configuration

These settings only affect the individual player's view:

• Mag_Limit: Sets the minimum brightness of stars to be rendered. Increasing this adds more faint stars.
• Star_Size: Adjusts the physical size of star points on the screen.
• Milky_Way_Brightness: Controls the opacity of the Milky Way texture.
• Atmospheric_Refraction: Toggles whether the atmosphere bends light near the horizon.

These settings affect the world logic and must be set by the server administrator or in the world save folder:

• Latitude: Determines the angle of celestial rotation.
• Longitude: Determines the offset of the celestial sphere.
• Day_Length: Changes how long a full day lasts in ticks.
• Year_Length: Changes how many days are in a year.
• Tick_Offset: Adjusts the starting position of the sun and stars.

Stellar Sky provides several commands to manage the sky simulation in real-time. Note that most commands require operator (OP) permissions.

Stellar Sky is primarily a rendering and mechanics mod and does not add a large variety of blocks or items to the game. Its focus is on the environment. However, it is designed to be compatible with other mods that add telescopes or navigation tools.

• Stellar API: While not an item in-game, this is a required library mod that handles the complex mathematical calculations for the sky. It allows other mods to query the position of the sun, moon, and stars for their own mechanics (such as solar panels or rituals).