Multiverse

Persistent randomized generation of the universe with extraterrestrial life.

Multiverse is a simple project that demonstrates the concept of persistent procedural generation with location-based random seeds. In this project, a 2D virtual galaxy is generated with celestial bodies, where properties of each are determined by a unique seed based on the location within the galaxy. User can navigate the galaxy to find planets with life, which are marked with a green ring around them.

Persistent Generation

The universe is generated procedurally, but the generation is persistent. This means that the same seed will always generate the same universe. On a 64-bit system, the universe is enormously large, on the order of $2^{64}$ by $2^{64}$ (or roughly $10^{19}$ by $10^{19}$) pixels. Given 500-by-500 pixels per screen, 20-by-20 grid size of the screen, and 10% probability of a body existing in each grid, there will be roughly $10^{28}$ bodies in this digital universe -- more than number of stars and plants in our (real) universe! Of course, the universe is not generated all at once. Instead, it is generated on-demand as the user navigates through the universe.

Unfortunately, not all the bodies are independent, as the generation is based on the location of the body. This is done by combining $x$ and $y$ coordinate of the bodies (with respect to the center of the universe) to form a 64-bit seed below

seed = (x & 0xFFFFFFFF) << 32 | (y & 0xFFFFFFFF)

Due to bit-shift and bitwise-or operations, there are roughly $10^{19}$ unique seeds. This means that there are at most $10^{19}$ unique bodies in the universe. This is still a large number -- considering that there are (only) roughly $10^{11}$ stars in the Milky Way.

Installation

1. clone the repository

   git clone https://github.com/ahemmatifar/multiverse.git

2. Change to project directory and install the project

   cd multiverse
   make dev_install

3. Run the project

   make run

4. Additionally, if interested to build from source, use

   make build

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgements

• Inspired by procedural generation of the universe by javidx9.
• The Pygame community for providing a great library for game development in Python.