cellauto3d

3D cellular automata with the Bevy game engine.

Features

• camera control using bevy_panorbit_camera
• parallel computation using rayon
• color selection using colorgrad
• basic in-game controls
• command line interface
• specify minimum and maximum population density in order to allow growth/shrinking cycles

Warning:

May produce flashing lights.

Compile and run

To download and compile, run

git clone https://www.github.com/elkasztano/cellauto3d && \
cd cellauto3d && \
cargo build --release

To compile and run in one go, navigate to the cellauto3d directory, then type

cargo run --release

Prerequisites for the Bevy game engine

Depending on your system, you may need to install some dependencies as described here:

https://github.com/bevyengine/bevy/blob/main/docs/linux_dependencies.md

Command line options

-h, --help

Show verbose help text including default values.

-d, --density

f64 floating point number specifying the density of the cubes at start. Ranges from 0.0 to 1.0.

A density of e.g. 0.5 means that roughly every other spot in the system is populated at the beginning.

-s, --seed

u64 integer seed for the pseudorandom number generator used to create the initial state.

-e, --edge-length

Integer value that defines the edge length of the space in which the automata live. Defaults to 64, which results in a 64x64x64 block system.

--maximum

f64 floating point number that defines the maximum density of spawned cubes. Ranges from 0.0 to 1.0. If the specified density is reached after a period of growth, no more new blocks will be spawned. Only despawning is allowed according to the defined rules, until the system has shrunk to the minimum. (see below)

--minimum

f64 floating point number that defines the minimum density at which growth of the system is allowed again. Ranges from 0.0 to 1.0.

-c, --color-gradient

Select color preset. The cubes are colored by choosing a color from the specified gradient. A newly spawned cube will have a slightly different color than its predecessors.

-l, --light-mode

Select lighting preset.

--fullscreen

Select fullscreen mode.

-r, --rules

String that defines the rules of the system.

Example:

'5-6/5/3/M' will result in the following rules:

• cells with five or six neighbours will survive
• new cells will spawn in empty spots with exactly five neighbours
• living cells have three states - if the survival conditions are not met, life will be reduced by one until it reaches zero, then the cube will despawn
• The 'M' at the end stands for Moore neighbourhood. Another possible option is 'VN', for the Von Neumann neighbourhood.

-f, --divisor

While in game, the user can hit 'm' to spawn new cubes in the center of the system. The size of this volume is defined by edge_length / divisor + 1, so in a 64x64x64 system a value of 10 will result in a 7x7x7 block in the center of the system in which new blocks are spawned.

--core-density

f64 floating point number defining the density of spawned cubes in the above specified center area when hitting 'm'.

In-game options

By default the camera is controlled with the mouse as described here.

Hit H to show help information.

Hit A to accelerate, and S to slow the system down.

Hit SPACE to stop the system entirely.

Hit N to spawn new cubes pseudorandomly in the entire volume.

Hit M to spawn new cubes in the center.

Hit R to temporarily disable mouse control and start a simple orbit animation, i.e. rotate around the system.

Press esc or Q to quit.

Example commands

cellauto3d will run fine without any parameters:

cargo run --release

Basic example resulting in cloud-like structures and a growth/shrinking cycle. Fullscreen mode and the 'bloom' effect is on:

cargo run --release -- -r "5-6/5/3/M" --maximum 0.1 --minimum 0.02 -c rainbow -l bloom -d 0.01 -s 9999999999 --fullscreen

Slower growth, let some smaller structures survive:

cargo run --release -- -c rainbow -l bloom --minimum 0.05 -r "3,6/6/4/M"

Hit M to start the simulation. Reaches a state with two oscillators and some stators after a few cycles:

cargo run --release -- -c rainbow -l bloom --minimum 0.063 -r "3,6/6/4/M" -d 0.0

Interesting growth pattern:

cargo run --release -- --minimum 0.04 --maximum 0.1 -r "5-10/6-7/4/M" -d 0.12 -s 42

References

https://conwaylife.com/wiki/Three-dimensional_cellular_automaton

https://softologyblog.wordpress.com/2019/12/28/3d-cellular-automata-3/